Auto merge of #2987 - rust-lang:rustup-2023-07-20, r=oli-obk

Automatic sync from rustc

230 files changed, 1699 insertions, 541 deletions

diff --git a/Cargo.lock b/Cargo.lock
index fb619d3870f..01445e97ae7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3488,6 +3488,7 @@ dependencies = [
  "rustc_trait_selection",
  "rustc_ty_utils",
  "serde_json",
+ "time",
  "tracing",
  "windows",
 ]
@@ -5143,6 +5144,33 @@ name = "tier-check"
 version = "0.1.0"
 
 [[package]]
+name = "time"
+version = "0.3.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea9e1b3cf1243ae005d9e74085d4d542f3125458f3a81af210d901dcd7411efd"
+dependencies = [
+ "itoa",
+ "serde",
+ "time-core",
+ "time-macros",
+]
+
+[[package]]
+name = "time-core"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7300fbefb4dadc1af235a9cef3737cea692a9d97e1b9cbcd4ebdae6f8868e6fb"
+
+[[package]]
+name = "time-macros"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "372950940a5f07bf38dbe211d7283c9e6d7327df53794992d293e534c733d09b"
+dependencies = [
+ "time-core",
+]
+
+[[package]]
 name = "tinystr"
 version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/RELEASES.md b/RELEASES.md
index 3205b02e5c4..e8c79c573f9 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -92,7 +92,6 @@ Cargo
 -----
 - [Allow named debuginfo options in `Cargo.toml`.](https://github.com/rust-lang/cargo/pull/11958/)
 - [Add `workspace_default_members` to the output of `cargo metadata`.](https://github.com/rust-lang/cargo/pull/11978/)
-- [`cargo add` now considers `rust-version` when selecting packages.](https://github.com/rust-lang/cargo/pull/12078/)
 - [Automatically inherit workspace fields when running `cargo new`/`cargo init`.](https://github.com/rust-lang/cargo/pull/12069/)
 
 <a id="1.71.0-Rustdoc"></a>
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 429e62c4a1c..9e193402feb 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1619,13 +1619,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 debug!(?hir_bounds);
 
                 let lifetime_mapping = if in_trait {
-                    self.arena.alloc_from_iter(
-                        collected_lifetime_mapping
-                            .iter()
-                            .map(|(lifetime, def_id)| (**lifetime, *def_id)),
+                    Some(
+                        &*self.arena.alloc_from_iter(
+                            collected_lifetime_mapping
+                                .iter()
+                                .map(|(lifetime, def_id)| (**lifetime, *def_id)),
+                        ),
                     )
                 } else {
-                    &mut []
+                    None
                 };
 
                 let opaque_ty_item = hir::OpaqueTy {
@@ -2090,13 +2092,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 debug!("lower_async_fn_ret_ty: generic_params={:#?}", generic_params);
 
                 let lifetime_mapping = if in_trait {
-                    self.arena.alloc_from_iter(
-                        collected_lifetime_mapping
-                            .iter()
-                            .map(|(lifetime, def_id)| (**lifetime, *def_id)),
+                    Some(
+                        &*self.arena.alloc_from_iter(
+                            collected_lifetime_mapping
+                                .iter()
+                                .map(|(lifetime, def_id)| (**lifetime, *def_id)),
+                        ),
                     )
                 } else {
-                    &mut []
+                    None
                 };
 
                 let opaque_ty_item = hir::OpaqueTy {
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 278e450c6b5..97c3e0b879a 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -695,7 +695,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 .find_map(find_fn_kind_from_did),
             ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => tcx
                 .explicit_item_bounds(def_id)
-                .arg_iter_copied(tcx, args)
+                .iter_instantiated_copied(tcx, args)
                 .find_map(|(clause, span)| find_fn_kind_from_did((clause, span))),
             ty::Closure(_, args) => match args.as_closure().kind() {
                 ty::ClosureKind::Fn => Some(hir::Mutability::Not),
diff --git a/compiler/rustc_codegen_cranelift/example/float-minmax-pass.rs b/compiler/rustc_codegen_cranelift/example/float-minmax-pass.rs
index b8f901d1ba1..80a2776ca1e 100644
--- a/compiler/rustc_codegen_cranelift/example/float-minmax-pass.rs
+++ b/compiler/rustc_codegen_cranelift/example/float-minmax-pass.rs
@@ -22,7 +22,7 @@ fn main() {
 
     #[cfg(not(any(target_arch = "mips", target_arch = "mips64")))]
     let nan = f32::NAN;
-    // MIPS hardware treats f32::NAN as SNAN. Clear the signaling bit.
+    // MIPS hardware except MIPS R6 treats f32::NAN as SNAN. Clear the signaling bit.
     // See https://github.com/rust-lang/rust/issues/52746.
     #[cfg(any(target_arch = "mips", target_arch = "mips64"))]
     let nan = f32::from_bits(f32::NAN.to_bits() - 1);
diff --git a/compiler/rustc_codegen_gcc/example/alloc_system.rs b/compiler/rustc_codegen_gcc/example/alloc_system.rs
index 046903fe5ac..e756b347e89 100644
--- a/compiler/rustc_codegen_gcc/example/alloc_system.rs
+++ b/compiler/rustc_codegen_gcc/example/alloc_system.rs
@@ -10,6 +10,7 @@
 #[cfg(any(target_arch = "x86",
               target_arch = "arm",
               target_arch = "mips",
+              target_arch = "mips32r6",
               target_arch = "powerpc",
               target_arch = "powerpc64"))]
 const MIN_ALIGN: usize = 8;
@@ -17,6 +18,7 @@ const MIN_ALIGN: usize = 8;
               target_arch = "aarch64",
               target_arch = "loongarch64",
               target_arch = "mips64",
+              target_arch = "mips64r6",
               target_arch = "s390x",
               target_arch = "sparc64"))]
 const MIN_ALIGN: usize = 16;
diff --git a/compiler/rustc_codegen_llvm/messages.ftl b/compiler/rustc_codegen_llvm/messages.ftl
index de1622951fe..aed4a8f3c85 100644
--- a/compiler/rustc_codegen_llvm/messages.ftl
+++ b/compiler/rustc_codegen_llvm/messages.ftl
@@ -1,7 +1,8 @@
 codegen_llvm_copy_bitcode = failed to copy bitcode to object file: {$err}
 
 codegen_llvm_dlltool_fail_import_library =
-    Dlltool could not create import library: {$stdout}
+    Dlltool could not create import library with {$dlltool_path} {$dlltool_args}:
+    {$stdout}
     {$stderr}
 
 codegen_llvm_dynamic_linking_with_lto =
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 39275272e42..4c69b9503a2 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -335,6 +335,10 @@ pub fn from_fn_attrs<'ll, 'tcx>(
     to_add.extend(probestack_attr(cx));
     to_add.extend(stackprotector_attr(cx));
 
+    if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_BUILTINS) {
+        to_add.push(llvm::CreateAttrString(cx.llcx, "no-builtins"));
+    }
+
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::COLD) {
         to_add.push(AttributeKind::Cold.create_attr(cx.llcx));
     }
diff --git a/compiler/rustc_codegen_llvm/src/back/archive.rs b/compiler/rustc_codegen_llvm/src/back/archive.rs
index a6416e9540c..10bf954d242 100644
--- a/compiler/rustc_codegen_llvm/src/back/archive.rs
+++ b/compiler/rustc_codegen_llvm/src/back/archive.rs
@@ -198,25 +198,24 @@ impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
                 "arm" => ("arm", "--32"),
                 _ => panic!("unsupported arch {}", sess.target.arch),
             };
-            let result = std::process::Command::new(&dlltool)
-                .args([
-                    "-d",
-                    def_file_path.to_str().unwrap(),
-                    "-D",
-                    lib_name,
-                    "-l",
-                    output_path.to_str().unwrap(),
-                    "-m",
-                    dlltool_target_arch,
-                    "-f",
-                    dlltool_target_bitness,
-                    "--no-leading-underscore",
-                    "--temp-prefix",
-                    temp_prefix.to_str().unwrap(),
-                ])
-                .output();
-
-            match result {
+            let mut dlltool_cmd = std::process::Command::new(&dlltool);
+            dlltool_cmd.args([
+                "-d",
+                def_file_path.to_str().unwrap(),
+                "-D",
+                lib_name,
+                "-l",
+                output_path.to_str().unwrap(),
+                "-m",
+                dlltool_target_arch,
+                "-f",
+                dlltool_target_bitness,
+                "--no-leading-underscore",
+                "--temp-prefix",
+                temp_prefix.to_str().unwrap(),
+            ]);
+
+            match dlltool_cmd.output() {
                 Err(e) => {
                     sess.emit_fatal(ErrorCallingDllTool {
                         dlltool_path: dlltool.to_string_lossy(),
@@ -226,6 +225,12 @@ impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
                 // dlltool returns '0' on failure, so check for error output instead.
                 Ok(output) if !output.stderr.is_empty() => {
                     sess.emit_fatal(DlltoolFailImportLibrary {
+                        dlltool_path: dlltool.to_string_lossy(),
+                        dlltool_args: dlltool_cmd
+                            .get_args()
+                            .map(|arg| arg.to_string_lossy())
+                            .collect::<Vec<_>>()
+                            .join(" "),
                         stdout: String::from_utf8_lossy(&output.stdout),
                         stderr: String::from_utf8_lossy(&output.stderr),
                     })
diff --git a/compiler/rustc_codegen_llvm/src/errors.rs b/compiler/rustc_codegen_llvm/src/errors.rs
index 44869ced1ae..fced6d504d2 100644
--- a/compiler/rustc_codegen_llvm/src/errors.rs
+++ b/compiler/rustc_codegen_llvm/src/errors.rs
@@ -81,6 +81,8 @@ pub(crate) struct ErrorCallingDllTool<'a> {
 #[derive(Diagnostic)]
 #[diag(codegen_llvm_dlltool_fail_import_library)]
 pub(crate) struct DlltoolFailImportLibrary<'a> {
+    pub dlltool_path: Cow<'a, str>,
+    pub dlltool_args: String,
     pub stdout: Cow<'a, str>,
     pub stderr: Cow<'a, str>,
 }
diff --git a/compiler/rustc_codegen_ssa/src/back/metadata.rs b/compiler/rustc_codegen_ssa/src/back/metadata.rs
index 1f827a2375d..e8b8665e39d 100644
--- a/compiler/rustc_codegen_ssa/src/back/metadata.rs
+++ b/compiler/rustc_codegen_ssa/src/back/metadata.rs
@@ -193,8 +193,8 @@ pub(crate) fn create_object_file(sess: &Session) -> Option<write::Object<'static
         }
         "x86" => Architecture::I386,
         "s390x" => Architecture::S390x,
-        "mips" => Architecture::Mips,
-        "mips64" => Architecture::Mips64,
+        "mips" | "mips32r6" => Architecture::Mips,
+        "mips64" | "mips64r6" => Architecture::Mips64,
         "x86_64" => {
             if sess.target.pointer_width == 32 {
                 Architecture::X86_64_X32
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index ececa29b231..1c5d7a7c68e 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -362,7 +362,7 @@ pub struct CodegenContext<B: WriteBackendMethods> {
 
 impl<B: WriteBackendMethods> CodegenContext<B> {
     pub fn create_diag_handler(&self) -> Handler {
-        Handler::with_emitter(true, None, Box::new(self.diag_emitter.clone()))
+        Handler::with_emitter(true, None, Box::new(self.diag_emitter.clone()), None)
     }
 
     pub fn config(&self, kind: ModuleKind) -> &ModuleConfig {
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index d6c23012762..0c7b8a79612 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -1,4 +1,4 @@
-use rustc_ast::{ast, MetaItemKind, NestedMetaItem};
+use rustc_ast::{ast, attr, MetaItemKind, NestedMetaItem};
 use rustc_attr::{list_contains_name, InlineAttr, InstructionSetAttr, OptimizeAttr};
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -60,6 +60,14 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, did: LocalDefId) -> CodegenFnAttrs {
         codegen_fn_attrs.flags |= CodegenFnAttrFlags::TRACK_CALLER;
     }
 
+    // When `no_builtins` is applied at the crate level, we should add the
+    // `no-builtins` attribute to each function to ensure it takes effect in LTO.
+    let crate_attrs = tcx.hir().attrs(rustc_hir::CRATE_HIR_ID);
+    let no_builtins = attr::contains_name(crate_attrs, sym::no_builtins);
+    if no_builtins {
+        codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_BUILTINS;
+    }
+
     let supported_target_features = tcx.supported_target_features(LOCAL_CRATE);
 
     let mut inline_span = None;
diff --git a/compiler/rustc_codegen_ssa/src/target_features.rs b/compiler/rustc_codegen_ssa/src/target_features.rs
index 7b5d83c612a..48c6c75bb1a 100644
--- a/compiler/rustc_codegen_ssa/src/target_features.rs
+++ b/compiler/rustc_codegen_ssa/src/target_features.rs
@@ -321,7 +321,7 @@ pub fn supported_target_features(sess: &Session) -> &'static [(&'static str, Opt
         "aarch64" => AARCH64_ALLOWED_FEATURES,
         "x86" | "x86_64" => X86_ALLOWED_FEATURES,
         "hexagon" => HEXAGON_ALLOWED_FEATURES,
-        "mips" | "mips64" => MIPS_ALLOWED_FEATURES,
+        "mips" | "mips32r6" | "mips64" | "mips64r6" => MIPS_ALLOWED_FEATURES,
         "powerpc" | "powerpc64" => POWERPC_ALLOWED_FEATURES,
         "riscv32" | "riscv64" => RISCV_ALLOWED_FEATURES,
         "wasm32" | "wasm64" => WASM_ALLOWED_FEATURES,
diff --git a/compiler/rustc_driver_impl/Cargo.toml b/compiler/rustc_driver_impl/Cargo.toml
index 67352c55c90..a7b01618ade 100644
--- a/compiler/rustc_driver_impl/Cargo.toml
+++ b/compiler/rustc_driver_impl/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 [lib]
 
 [dependencies]
+time = { version = "0.3", default-features = false, features = ["formatting", ] }
 tracing = { version = "0.1.35" }
 serde_json = "1.0.59"
 rustc_log = { path = "../rustc_log" }
diff --git a/compiler/rustc_driver_impl/messages.ftl b/compiler/rustc_driver_impl/messages.ftl
index 22b4ec6b0d1..9b2f2c33860 100644
--- a/compiler/rustc_driver_impl/messages.ftl
+++ b/compiler/rustc_driver_impl/messages.ftl
@@ -3,7 +3,11 @@ driver_impl_ice_bug_report = we would appreciate a bug report: {$bug_report_url}
 driver_impl_ice_exclude_cargo_defaults = some of the compiler flags provided by cargo are hidden
 
 driver_impl_ice_flags = compiler flags: {$flags}
+driver_impl_ice_path = please attach the file at `{$path}` to your bug report
+driver_impl_ice_path_error = the ICE couldn't be written to `{$path}`: {$error}
+driver_impl_ice_path_error_env = the environment variable `RUSTC_ICE` is set to `{$env_var}`
 driver_impl_ice_version = rustc {$version} running on {$triple}
+
 driver_impl_rlink_empty_version_number = The input does not contain version number
 
 driver_impl_rlink_encoding_version_mismatch = .rlink file was produced with encoding version `{$version_array}`, but the current version is `{$rlink_version}`
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 25c043149e8..11303e7d09e 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -7,6 +7,8 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(lazy_cell)]
 #![feature(decl_macro)]
+#![feature(ice_to_disk)]
+#![feature(let_chains)]
 #![recursion_limit = "256"]
 #![allow(rustc::potential_query_instability)]
 #![deny(rustc::untranslatable_diagnostic)]
@@ -57,8 +59,11 @@ use std::panic::{self, catch_unwind};
 use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::str;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::OnceLock;
-use std::time::Instant;
+use std::time::{Instant, SystemTime};
+use time::format_description::well_known::Rfc3339;
+use time::OffsetDateTime;
 
 #[allow(unused_macros)]
 macro do_not_use_print($($t:tt)*) {
@@ -294,6 +299,7 @@ fn run_compiler(
         input: Input::File(PathBuf::new()),
         output_file: ofile,
         output_dir: odir,
+        ice_file: ice_path().clone(),
         file_loader,
         locale_resources: DEFAULT_LOCALE_RESOURCES,
         lint_caps: Default::default(),
@@ -1292,9 +1298,29 @@ pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
     }
 }
 
-/// Stores the default panic hook, from before [`install_ice_hook`] was called.
-static DEFAULT_HOOK: OnceLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
-    OnceLock::new();
+pub static ICE_PATH: OnceLock<Option<PathBuf>> = OnceLock::new();
+
+pub fn ice_path() -> &'static Option<PathBuf> {
+    ICE_PATH.get_or_init(|| {
+        if !rustc_feature::UnstableFeatures::from_environment(None).is_nightly_build() {
+            return None;
+        }
+        if let Ok("0") = std::env::var("RUST_BACKTRACE").as_deref() {
+            return None;
+        }
+        let mut path = match std::env::var("RUSTC_ICE").as_deref() {
+            // Explicitly opting out of writing ICEs to disk.
+            Ok("0") => return None,
+            Ok(s) => PathBuf::from(s),
+            Err(_) => std::env::current_dir().unwrap_or_default(),
+        };
+        let now: OffsetDateTime = SystemTime::now().into();
+        let file_now = now.format(&Rfc3339).unwrap_or(String::new());
+        let pid = std::process::id();
+        path.push(format!("rustc-ice-{file_now}-{pid}.txt"));
+        Some(path)
+    })
+}
 
 /// Installs a panic hook that will print the ICE message on unexpected panics.
 ///
@@ -1318,8 +1344,6 @@ pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler))
         std::env::set_var("RUST_BACKTRACE", "full");
     }
 
-    let default_hook = DEFAULT_HOOK.get_or_init(panic::take_hook);
-
     panic::set_hook(Box::new(move |info| {
         // If the error was caused by a broken pipe then this is not a bug.
         // Write the error and return immediately. See #98700.
@@ -1336,7 +1360,7 @@ pub fn install_ice_hook(bug_report_url: &'static str, extra_info: fn(&Handler))
         // Invoke the default handler, which prints the actual panic message and optionally a backtrace
         // Don't do this for delayed bugs, which already emit their own more useful backtrace.
         if !info.payload().is::<rustc_errors::DelayedBugPanic>() {
-            (*default_hook)(info);
+            std::panic_hook_with_disk_dump(info, ice_path().as_deref());
 
             // Separate the output with an empty line
             eprintln!();
@@ -1368,7 +1392,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info:
         false,
         TerminalUrl::No,
     ));
-    let handler = rustc_errors::Handler::with_emitter(true, None, emitter);
+    let handler = rustc_errors::Handler::with_emitter(true, None, emitter, None);
 
     // a .span_bug or .bug call has already printed what
     // it wants to print.
@@ -1379,10 +1403,40 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info:
     }
 
     handler.emit_note(session_diagnostics::IceBugReport { bug_report_url });
-    handler.emit_note(session_diagnostics::IceVersion {
-        version: util::version_str!().unwrap_or("unknown_version"),
-        triple: config::host_triple(),
-    });
+
+    let version = util::version_str!().unwrap_or("unknown_version");
+    let triple = config::host_triple();
+
+    static FIRST_PANIC: AtomicBool = AtomicBool::new(true);
+
+    let file = if let Some(path) = ice_path().as_ref() {
+        // Create the ICE dump target file.
+        match crate::fs::File::options().create(true).append(true).open(&path) {
+            Ok(mut file) => {
+                handler
+                    .emit_note(session_diagnostics::IcePath { path: path.display().to_string() });
+                if FIRST_PANIC.swap(false, Ordering::SeqCst) {
+                    let _ = write!(file, "\n\nrustc version: {version}\nplatform: {triple}");
+                }
+                Some(file)
+            }
+            Err(err) => {
+                // The path ICE couldn't be written to disk, provide feedback to the user as to why.
+                handler.emit_warning(session_diagnostics::IcePathError {
+                    path: path.display().to_string(),
+                    error: err.to_string(),
+                    env_var: std::env::var("RUSTC_ICE")
+                        .ok()
+                        .map(|env_var| session_diagnostics::IcePathErrorEnv { env_var }),
+                });
+                handler.emit_note(session_diagnostics::IceVersion { version, triple });
+                None
+            }
+        }
+    } else {
+        handler.emit_note(session_diagnostics::IceVersion { version, triple });
+        None
+    };
 
     if let Some((flags, excluded_cargo_defaults)) = extra_compiler_flags() {
         handler.emit_note(session_diagnostics::IceFlags { flags: flags.join(" ") });
@@ -1396,7 +1450,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str, extra_info:
 
     let num_frames = if backtrace { None } else { Some(2) };
 
-    interface::try_print_query_stack(&handler, num_frames);
+    interface::try_print_query_stack(&handler, num_frames, file);
 
     // We don't trust this callback not to panic itself, so run it at the end after we're sure we've
     // printed all the relevant info.
diff --git a/compiler/rustc_driver_impl/src/session_diagnostics.rs b/compiler/rustc_driver_impl/src/session_diagnostics.rs
index 638b368f702..f7f06b7d0f2 100644
--- a/compiler/rustc_driver_impl/src/session_diagnostics.rs
+++ b/compiler/rustc_driver_impl/src/session_diagnostics.rs
@@ -1,4 +1,4 @@
-use rustc_macros::Diagnostic;
+use rustc_macros::{Diagnostic, Subdiagnostic};
 
 #[derive(Diagnostic)]
 #[diag(driver_impl_rlink_unable_to_read)]
@@ -57,6 +57,27 @@ pub(crate) struct IceVersion<'a> {
 }
 
 #[derive(Diagnostic)]
+#[diag(driver_impl_ice_path)]
+pub(crate) struct IcePath {
+    pub path: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(driver_impl_ice_path_error)]
+pub(crate) struct IcePathError {
+    pub path: String,
+    pub error: String,
+    #[subdiagnostic]
+    pub env_var: Option<IcePathErrorEnv>,
+}
+
+#[derive(Subdiagnostic)]
+#[note(driver_impl_ice_path_error_env)]
+pub(crate) struct IcePathErrorEnv {
+    pub env_var: String,
+}
+
+#[derive(Diagnostic)]
 #[diag(driver_impl_ice_flags)]
 pub(crate) struct IceFlags {
     pub flags: String,
diff --git a/compiler/rustc_error_codes/src/error_codes/E0391.md b/compiler/rustc_error_codes/src/error_codes/E0391.md
index dff50ccaa0b..457fbd002a1 100644
--- a/compiler/rustc_error_codes/src/error_codes/E0391.md
+++ b/compiler/rustc_error_codes/src/error_codes/E0391.md
@@ -14,3 +14,6 @@ trait SecondTrait : FirstTrait {
 
 The previous example contains a circular dependency between two traits:
 `FirstTrait` depends on `SecondTrait` which itself depends on `FirstTrait`.
+
+See https://rustc-dev-guide.rust-lang.org/overview.html#queries and
+https://rustc-dev-guide.rust-lang.org/query.html for more information.
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index 51e1fe531dd..1879ece59e3 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -354,6 +354,13 @@ impl DiagnosticMessage {
             }
         }
     }
+
+    pub fn as_str(&self) -> Option<&str> {
+        match self {
+            DiagnosticMessage::Eager(s) | DiagnosticMessage::Str(s) => Some(s),
+            DiagnosticMessage::FluentIdentifier(_, _) => None,
+        }
+    }
 }
 
 impl From<String> for DiagnosticMessage {
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 9d4d159fd96..a0fa4115c3e 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1982,7 +1982,7 @@ impl EmitterWriter {
                 // We special case `#[derive(_)]\n` and other attribute suggestions, because those
                 // are the ones where context is most useful.
                 let file_lines = sm
-                    .span_to_lines(span.primary_span().unwrap().shrink_to_hi())
+                    .span_to_lines(parts[0].span.shrink_to_hi())
                     .expect("span_to_lines failed when emitting suggestion");
                 let line_num = sm.lookup_char_pos(parts[0].span.lo()).line;
                 if let Some(line) = file_lines.file.get_line(line_num - 1) {
diff --git a/compiler/rustc_errors/src/json/tests.rs b/compiler/rustc_errors/src/json/tests.rs
index 671dc449eaa..db0dd4ffe8e 100644
--- a/compiler/rustc_errors/src/json/tests.rs
+++ b/compiler/rustc_errors/src/json/tests.rs
@@ -64,7 +64,7 @@ fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) {
         );
 
         let span = Span::with_root_ctxt(BytePos(span.0), BytePos(span.1));
-        let handler = Handler::with_emitter(true, None, Box::new(je));
+        let handler = Handler::with_emitter(true, None, Box::new(je), None);
         handler.span_err(span, "foo");
 
         let bytes = output.lock().unwrap();
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index b9db25103a3..1da02e1bb01 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -47,9 +47,10 @@ use std::borrow::Cow;
 use std::error::Report;
 use std::fmt;
 use std::hash::Hash;
+use std::io::Write;
 use std::num::NonZeroUsize;
 use std::panic;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use termcolor::{Color, ColorSpec};
 
@@ -461,6 +462,10 @@ struct HandlerInner {
     ///
     /// [RFC-2383]: https://rust-lang.github.io/rfcs/2383-lint-reasons.html
     fulfilled_expectations: FxHashSet<LintExpectationId>,
+
+    /// The file where the ICE information is stored. This allows delayed_span_bug backtraces to be
+    /// stored along side the main panic backtrace.
+    ice_file: Option<PathBuf>,
 }
 
 /// A key denoting where from a diagnostic was stashed.
@@ -550,6 +555,7 @@ impl Handler {
         sm: Option<Lrc<SourceMap>>,
         fluent_bundle: Option<Lrc<FluentBundle>>,
         fallback_bundle: LazyFallbackBundle,
+        ice_file: Option<PathBuf>,
     ) -> Self {
         Self::with_tty_emitter_and_flags(
             color_config,
@@ -557,6 +563,7 @@ impl Handler {
             fluent_bundle,
             fallback_bundle,
             HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
+            ice_file,
         )
     }
 
@@ -566,6 +573,7 @@ impl Handler {
         fluent_bundle: Option<Lrc<FluentBundle>>,
         fallback_bundle: LazyFallbackBundle,
         flags: HandlerFlags,
+        ice_file: Option<PathBuf>,
     ) -> Self {
         let emitter = Box::new(EmitterWriter::stderr(
             color_config,
@@ -579,23 +587,26 @@ impl Handler {
             flags.track_diagnostics,
             TerminalUrl::No,
         ));
-        Self::with_emitter_and_flags(emitter, flags)
+        Self::with_emitter_and_flags(emitter, flags, ice_file)
     }
 
     pub fn with_emitter(
         can_emit_warnings: bool,
         treat_err_as_bug: Option<NonZeroUsize>,
         emitter: Box<dyn Emitter + sync::Send>,
+        ice_file: Option<PathBuf>,
     ) -> Self {
         Handler::with_emitter_and_flags(
             emitter,
             HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
+            ice_file,
         )
     }
 
     pub fn with_emitter_and_flags(
         emitter: Box<dyn Emitter + sync::Send>,
         flags: HandlerFlags,
+        ice_file: Option<PathBuf>,
     ) -> Self {
         Self {
             flags,
@@ -618,6 +629,7 @@ impl Handler {
                 check_unstable_expect_diagnostics: false,
                 unstable_expect_diagnostics: Vec::new(),
                 fulfilled_expectations: Default::default(),
+                ice_file,
             }),
         }
     }
@@ -991,7 +1003,7 @@ impl Handler {
         self.emit_diag_at_span(Diagnostic::new_with_code(Warning(None), Some(code), msg), span);
     }
 
-    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<String>) -> ! {
         self.inner.borrow_mut().span_bug(span, msg)
     }
 
@@ -1000,7 +1012,7 @@ impl Handler {
     pub fn delay_span_bug(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<String>,
     ) -> ErrorGuaranteed {
         self.inner.borrow_mut().delay_span_bug(span, msg)
     }
@@ -1584,8 +1596,8 @@ impl HandlerInner {
     }
 
     #[track_caller]
-    fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! {
-        self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp);
+    fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: impl Into<String>) -> ! {
+        self.emit_diag_at_span(Diagnostic::new(Bug, msg.into()), sp);
         panic::panic_any(ExplicitBug);
     }
 
@@ -1598,7 +1610,7 @@ impl HandlerInner {
     fn delay_span_bug(
         &mut self,
         sp: impl Into<MultiSpan>,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<String>,
     ) -> ErrorGuaranteed {
         // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
         // incrementing `err_count` by one, so we need to +1 the comparing.
@@ -1607,9 +1619,9 @@ impl HandlerInner {
             self.err_count() + self.lint_err_count + self.delayed_bug_count() + 1 >= c.get()
         }) {
             // FIXME: don't abort here if report_delayed_bugs is off
-            self.span_bug(sp, msg);
+            self.span_bug(sp, msg.into());
         }
-        let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg);
+        let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg.into());
         diagnostic.set_span(sp.into());
         self.emit_diagnostic(&mut diagnostic).unwrap()
     }
@@ -1657,8 +1669,21 @@ impl HandlerInner {
         explanation: impl Into<DiagnosticMessage> + Copy,
     ) {
         let mut no_bugs = true;
+        // If backtraces are enabled, also print the query stack
+        let backtrace = std::env::var_os("RUST_BACKTRACE").map_or(true, |x| &x != "0");
         for bug in bugs {
-            let mut bug = bug.decorate();
+            if let Some(file) = self.ice_file.as_ref()
+                && let Ok(mut out) = std::fs::File::options().append(true).open(file)
+            {
+                let _ = write!(
+                    &mut out,
+                    "\n\ndelayed span bug: {}\n{}",
+                    bug.inner.styled_message().iter().filter_map(|(msg, _)| msg.as_str()).collect::<String>(),
+                    &bug.note
+                );
+            }
+            let mut bug =
+                if backtrace || self.ice_file.is_none() { bug.decorate() } else { bug.inner };
 
             if no_bugs {
                 // Put the overall explanation before the `DelayedBug`s, to
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 4b0907cf15a..12473a2bb0b 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -1147,7 +1147,7 @@ impl<'a> ExtCtxt<'a> {
     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) {
         self.sess.parse_sess.span_diagnostic.span_warn(sp, msg);
     }
-    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) -> ! {
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<String>) -> ! {
         self.sess.parse_sess.span_diagnostic.span_bug(sp, msg);
     }
     pub fn trace_macros_diag(&mut self) {
diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index 42cc0a6b143..102bae2a744 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -1200,7 +1200,7 @@ fn check_matcher_core<'tt>(
                             err.span_label(sp, format!("not allowed after `{}` fragments", kind));
 
                             if kind == NonterminalKind::PatWithOr
-                                && sess.edition.rust_2021()
+                                && sess.edition.at_least_rust_2021()
                                 && next_token.is_token(&BinOp(token::BinOpToken::Or))
                             {
                                 let suggestion = quoted_tt_to_string(&TokenTree::MetaVarDecl(
diff --git a/compiler/rustc_expand/src/tests.rs b/compiler/rustc_expand/src/tests.rs
index 8a5e09475ff..6490e52955d 100644
--- a/compiler/rustc_expand/src/tests.rs
+++ b/compiler/rustc_expand/src/tests.rs
@@ -161,7 +161,7 @@ fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &
             false,
             TerminalUrl::No,
         );
-        let handler = Handler::with_emitter(true, None, Box::new(emitter));
+        let handler = Handler::with_emitter(true, None, Box::new(emitter), None);
         #[allow(rustc::untranslatable_diagnostic)]
         handler.span_err(msp, "foo");
 
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 35ef30114b7..68f1559ea22 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2664,10 +2664,19 @@ pub struct OpaqueTy<'hir> {
     pub generics: &'hir Generics<'hir>,
     pub bounds: GenericBounds<'hir>,
     pub origin: OpaqueTyOrigin,
-    // Opaques have duplicated lifetimes, this mapping connects the original lifetime with the copy
-    // so we can later generate bidirectional outlives predicates to enforce that these lifetimes
-    // stay in sync.
-    pub lifetime_mapping: &'hir [(Lifetime, LocalDefId)],
+    /// Return-position impl traits (and async futures) must "reify" any late-bound
+    /// lifetimes that are captured from the function signature they originate from.
+    ///
+    /// This is done by generating a new early-bound lifetime parameter local to the
+    /// opaque which is substituted in the function signature with the late-bound
+    /// lifetime.
+    ///
+    /// This mapping associated a captured lifetime (first parameter) with the new
+    /// early-bound lifetime that was generated for the opaque.
+    pub lifetime_mapping: Option<&'hir [(Lifetime, LocalDefId)]>,
+    /// Whether the opaque is a return-position impl trait (or async future)
+    /// originating from a trait method. This makes it so that the opaque is
+    /// lowered as an associated type.
     pub in_trait: bool,
 }
 
diff --git a/compiler/rustc_hir_analysis/src/astconv/lint.rs b/compiler/rustc_hir_analysis/src/astconv/lint.rs
index 05a3ab63d5c..ff55174f97a 100644
--- a/compiler/rustc_hir_analysis/src/astconv/lint.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/lint.rs
@@ -86,7 +86,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                 ));
             }
 
-            if self_ty.span.edition().rust_2021() {
+            if self_ty.span.edition().at_least_rust_2021() {
                 let msg = "trait objects must include the `dyn` keyword";
                 let label = "add `dyn` keyword before this trait";
                 let mut diag =
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index 07f8dd948e2..89877280a73 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -867,7 +867,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ImplTraitInTraitCollector<'_, 'tcx> {
             });
             self.types.insert(proj.def_id, (infer_ty, proj.args));
             // Recurse into bounds
-            for (pred, pred_span) in self.interner().explicit_item_bounds(proj.def_id).arg_iter_copied(self.interner(), proj.args) {
+            for (pred, pred_span) in self.interner().explicit_item_bounds(proj.def_id).iter_instantiated_copied(self.interner(), proj.args) {
                 let pred = pred.fold_with(self);
                 let pred = self.ocx.normalize(
                     &ObligationCause::misc(self.span, self.body_id),
@@ -2149,7 +2149,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     let obligations: Vec<_> = tcx
         .explicit_item_bounds(trait_ty.def_id)
-        .arg_iter_copied(tcx, rebased_args)
+        .iter_instantiated_copied(tcx, rebased_args)
         .map(|(concrete_ty_bound, span)| {
             debug!("check_type_bounds: concrete_ty_bound = {:?}", concrete_ty_bound);
             traits::Obligation::new(tcx, mk_cause(span), param_env, concrete_ty_bound)
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 5ff33763e13..def7a3a9d88 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -409,7 +409,7 @@ fn fn_sig_suggestion<'tcx>(
     let asyncness = if tcx.asyncness(assoc.def_id).is_async() {
         output = if let ty::Alias(_, alias_ty) = *output.kind() {
             tcx.explicit_item_bounds(alias_ty.def_id)
-                .arg_iter_copied(tcx, alias_ty.args)
+                .iter_instantiated_copied(tcx, alias_ty.args)
                 .find_map(|(bound, _)| bound.as_projection_clause()?.no_bound_vars()?.term.ty())
                 .unwrap_or_else(|| {
                     span_bug!(
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 443d072f992..4e194f1c381 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -1567,7 +1567,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ImplTraitInTraitFinder<'_, 'tcx> {
             });
             for (bound, bound_span) in tcx
                 .explicit_item_bounds(opaque_ty.def_id)
-                .arg_iter_copied(tcx, opaque_ty.args)
+                .iter_instantiated_copied(tcx, opaque_ty.args)
             {
                 let bound = self.wfcx.normalize(bound_span, None, bound);
                 self.wfcx.register_obligations(traits::wf::predicate_obligations(
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 1c9070600db..979b101e7fe 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -66,7 +66,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
             let opaque_ty_id = tcx.hir().local_def_id_to_hir_id(opaque_def_id.expect_local());
             let opaque_ty_node = tcx.hir().get(opaque_ty_id);
             let Node::Item(&Item {
-                kind: ItemKind::OpaqueTy(OpaqueTy { lifetime_mapping, .. }),
+                kind: ItemKind::OpaqueTy(OpaqueTy { lifetime_mapping: Some(lifetime_mapping), .. }),
                 ..
             }) = opaque_ty_node
             else {
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 199cdabb7e9..1ef257e87d6 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -145,7 +145,7 @@ fn variance_of_opaque(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Varianc
     let mut collector =
         OpaqueTypeLifetimeCollector { tcx, root_def_id: item_def_id.to_def_id(), variances };
     let id_args = ty::GenericArgs::identity_for_item(tcx, item_def_id);
-    for (pred, _) in tcx.explicit_item_bounds(item_def_id).arg_iter_copied(tcx, id_args) {
+    for (pred, _) in tcx.explicit_item_bounds(item_def_id).iter_instantiated_copied(tcx, id_args) {
         debug!(?pred);
 
         // We only ignore opaque type args if the opaque type is the outermost type.
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index f2a43cc414d..119ed2fa408 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -551,8 +551,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
 
                 for ty in [first_ty, second_ty] {
-                    for (clause, _) in
-                        self.tcx.explicit_item_bounds(rpit_def_id).arg_iter_copied(self.tcx, args)
+                    for (clause, _) in self
+                        .tcx
+                        .explicit_item_bounds(rpit_def_id)
+                        .iter_instantiated_copied(self.tcx, args)
                     {
                         let pred = clause.kind().rebind(match clause.kind().skip_binder() {
                             ty::ClauseKind::Trait(trait_pred) => {
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index e7df9ecf383..affeee55e79 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -177,7 +177,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     expected_ty,
                     self.tcx
                         .explicit_item_bounds(def_id)
-                        .arg_iter_copied(self.tcx, args)
+                        .iter_instantiated_copied(self.tcx, args)
                         .map(|(c, s)| (c.as_predicate(), s)),
                 ),
             ty::Dynamic(ref object_type, ..) => {
@@ -720,13 +720,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => self
                 .tcx
                 .explicit_item_bounds(def_id)
-                .arg_iter_copied(self.tcx, args)
+                .iter_instantiated_copied(self.tcx, args)
                 .find_map(|(p, s)| get_future_output(p.as_predicate(), s))?,
             ty::Error(_) => return None,
             ty::Alias(ty::Projection, proj) if self.tcx.is_impl_trait_in_trait(proj.def_id) => self
                 .tcx
                 .explicit_item_bounds(proj.def_id)
-                .arg_iter_copied(self.tcx, proj.args)
+                .iter_instantiated_copied(self.tcx, proj.args)
                 .find_map(|(p, s)| get_future_output(p.as_predicate(), s))?,
             _ => span_bug!(
                 self.tcx.def_span(expr_def_id),
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index bd7e7a671e6..94f64a1ffdb 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -860,7 +860,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             .resolve_fully_qualified_call(span, item_name, ty.normalized, qself.span, hir_id)
             .and_then(|r| {
                 // lint bare trait if the method is found in the trait
-                if span.edition().rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
+                if span.edition().at_least_rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
                     diag.emit();
                 }
                 Ok(r)
@@ -890,7 +890,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 }
 
                 // emit or cancel the diagnostic for bare traits
-                if span.edition().rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
+                if span.edition().at_least_rust_2021() && let Some(mut diag) = self.tcx.sess.diagnostic().steal_diagnostic(qself.span, StashKey::TraitMissingMethod) {
                     if trait_missing_method {
                         // cancel the diag for bare traits when meeting `MyTrait::missing_method`
                         diag.cancel();
@@ -908,7 +908,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         error,
                         None,
                         Expectation::NoExpectation,
-                        trait_missing_method && span.edition().rust_2021(), // emits missing method for trait only after edition 2021
+                        trait_missing_method && span.edition().at_least_rust_2021(), // emits missing method for trait only after edition 2021
                     ) {
                         e.emit();
                     }
diff --git a/compiler/rustc_hir_typeck/src/method/prelude2021.rs b/compiler/rustc_hir_typeck/src/method/prelude2021.rs
index ec4e7f7f88a..4efe95c4dc5 100644
--- a/compiler/rustc_hir_typeck/src/method/prelude2021.rs
+++ b/compiler/rustc_hir_typeck/src/method/prelude2021.rs
@@ -32,7 +32,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
 
         // Rust 2021 and later is already using the new prelude
-        if span.rust_2021() {
+        if span.at_least_rust_2021() {
             return;
         }
 
@@ -203,7 +203,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         pick: &Pick<'tcx>,
     ) {
         // Rust 2021 and later is already using the new prelude
-        if span.rust_2021() {
+        if span.at_least_rust_2021() {
             return;
         }
 
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 9ef97243c5e..05eed1923d1 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -437,7 +437,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // this case used to be allowed by the compiler,
                 // so we do a future-compat lint here for the 2015 edition
                 // (see https://github.com/rust-lang/rust/issues/46906)
-                if self.tcx.sess.rust_2018() {
+                if self.tcx.sess.at_least_rust_2018() {
                     self.tcx.sess.emit_err(MethodCallOnUnknownRawPointee { span });
                 } else {
                     self.tcx.struct_span_lint_hir(
@@ -1592,7 +1592,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                     if let Some(method_name) = self.method_name {
                         // Some trait methods are excluded for arrays before 2021.
                         // (`array.into_iter()` wants a slice iterator for compatibility.)
-                        if self_ty.is_array() && !method_name.span.rust_2021() {
+                        if self_ty.is_array() && !method_name.span.at_least_rust_2021() {
                             let trait_def = self.tcx.trait_def(trait_ref.def_id);
                             if trait_def.skip_array_during_method_dispatch {
                                 return ProbeResult::NoMatch;
diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs
index f77a4d16b5f..fb81a8395d7 100644
--- a/compiler/rustc_hir_typeck/src/upvar.rs
+++ b/compiler/rustc_hir_typeck/src/upvar.rs
@@ -2001,7 +2001,7 @@ fn should_do_rust_2021_incompatible_closure_captures_analysis(
     tcx: TyCtxt<'_>,
     closure_id: hir::HirId,
 ) -> bool {
-    if tcx.sess.rust_2021() {
+    if tcx.sess.at_least_rust_2021() {
         return false;
     }
 
@@ -2247,5 +2247,5 @@ fn truncate_capture_for_optimization(
 fn enable_precise_capture(span: Span) -> bool {
     // We use span here to ensure that if the closure was generated by a macro with a different
     // edition.
-    span.rust_2021()
+    span.at_least_rust_2021()
 }
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index cf6c7f70de3..2329a1f63ce 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -3,7 +3,6 @@
 // substitutions.
 
 use crate::FnCtxt;
-use hir::def_id::LocalDefId;
 use rustc_data_structures::unord::ExtendUnord;
 use rustc_errors::{ErrorGuaranteed, StashKey};
 use rustc_hir as hir;
@@ -11,13 +10,12 @@ use rustc_hir::intravisit::{self, Visitor};
 use rustc_infer::infer::error_reporting::TypeAnnotationNeeded::E0282;
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, PointerCoercion};
 use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
-use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable, TypeVisitableExt};
+use rustc_middle::ty::visit::TypeVisitableExt;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 
 use std::mem;
-use std::ops::ControlFlow;
 
 ///////////////////////////////////////////////////////////////////////////
 // Entry point
@@ -565,23 +563,9 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             let hidden_type = self.resolve(decl.hidden_type, &decl.hidden_type.span);
             let opaque_type_key = self.resolve(opaque_type_key, &decl.hidden_type.span);
 
-            struct RecursionChecker {
-                def_id: LocalDefId,
-            }
-            impl<'tcx> ty::TypeVisitor<TyCtxt<'tcx>> for RecursionChecker {
-                type BreakTy = ();
-                fn visit_ty(&mut self, t: Ty<'tcx>) -> ControlFlow<Self::BreakTy> {
-                    if let ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) = *t.kind() {
-                        if def_id == self.def_id.to_def_id() {
-                            return ControlFlow::Break(());
-                        }
-                    }
-                    t.super_visit_with(self)
-                }
-            }
-            if hidden_type
-                .visit_with(&mut RecursionChecker { def_id: opaque_type_key.def_id })
-                .is_break()
+            if let ty::Alias(ty::Opaque, alias_ty) = hidden_type.ty.kind()
+                && alias_ty.def_id == opaque_type_key.def_id.to_def_id()
+                && alias_ty.args == opaque_type_key.args
             {
                 continue;
             }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index bf46f9881d4..8e3c76d6a4b 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -403,7 +403,7 @@ impl<'tcx> InferCtxt<'tcx> {
         let future_trait = self.tcx.require_lang_item(LangItem::Future, None);
         let item_def_id = self.tcx.associated_item_def_ids(future_trait)[0];
 
-        self.tcx.explicit_item_bounds(def_id).arg_iter_copied(self.tcx, args).find_map(
+        self.tcx.explicit_item_bounds(def_id).iter_instantiated_copied(self.tcx, args).find_map(
             |(predicate, _)| {
                 predicate
                     .kind()
diff --git a/compiler/rustc_infer/src/infer/opaque_types.rs b/compiler/rustc_infer/src/infer/opaque_types.rs
index 90f0b4ce401..945136fbff2 100644
--- a/compiler/rustc_infer/src/infer/opaque_types.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types.rs
@@ -591,7 +591,7 @@ impl<'tcx> InferCtxt<'tcx> {
         let tcx = self.tcx;
         let item_bounds = tcx.explicit_item_bounds(def_id);
 
-        for (predicate, _) in item_bounds.arg_iter_copied(tcx, args) {
+        for (predicate, _) in item_bounds.iter_instantiated_copied(tcx, args) {
             let predicate = predicate.fold_with(&mut BottomUpFolder {
                 tcx,
                 ty_op: |ty| match *ty.kind() {
diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs
index 1e1ecd3fb94..2bc6546ba28 100644
--- a/compiler/rustc_infer/src/infer/outlives/verify.rs
+++ b/compiler/rustc_infer/src/infer/outlives/verify.rs
@@ -295,7 +295,7 @@ impl<'cx, 'tcx> VerifyBoundCx<'cx, 'tcx> {
         let bounds = tcx.item_bounds(alias_ty.def_id);
         trace!("{:#?}", bounds.skip_binder());
         bounds
-            .arg_iter(tcx, alias_ty.args)
+            .iter_instantiated(tcx, alias_ty.args)
             .filter_map(|p| p.as_type_outlives_clause())
             .filter_map(|p| p.no_bound_vars())
             .map(|OutlivesPredicate(_, r)| r)
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 3f420f19efe..5b417e008cf 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -251,6 +251,7 @@ pub struct Config {
     pub input: Input,
     pub output_dir: Option<PathBuf>,
     pub output_file: Option<OutFileName>,
+    pub ice_file: Option<PathBuf>,
     pub file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
     pub locale_resources: &'static [&'static str],
 
@@ -315,6 +316,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
                 config.lint_caps,
                 config.make_codegen_backend,
                 registry.clone(),
+                config.ice_file,
             );
 
             if let Some(parse_sess_created) = config.parse_sess_created {
@@ -346,7 +348,11 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
     )
 }
 
-pub fn try_print_query_stack(handler: &Handler, num_frames: Option<usize>) {
+pub fn try_print_query_stack(
+    handler: &Handler,
+    num_frames: Option<usize>,
+    file: Option<std::fs::File>,
+) {
     eprintln!("query stack during panic:");
 
     // Be careful relying on global state here: this code is called from
@@ -358,7 +364,8 @@ pub fn try_print_query_stack(handler: &Handler, num_frames: Option<usize>) {
                 QueryCtxt::new(icx.tcx),
                 icx.query,
                 handler,
-                num_frames
+                num_frames,
+                file,
             ))
         } else {
             0
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 09141afd137..5c6c3491b38 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -67,6 +67,7 @@ fn mk_session(handler: &mut EarlyErrorHandler, matches: getopts::Matches) -> (Se
         None,
         None,
         "",
+        None,
     );
     (sess, cfg)
 }
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index 035ea2414f7..12d33f06309 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -70,6 +70,7 @@ pub fn create_session(
         Box<dyn FnOnce(&config::Options) -> Box<dyn CodegenBackend> + Send>,
     >,
     descriptions: Registry,
+    ice_file: Option<PathBuf>,
 ) -> (Session, Box<dyn CodegenBackend>) {
     let codegen_backend = if let Some(make_codegen_backend) = make_codegen_backend {
         make_codegen_backend(&sopts)
@@ -111,6 +112,7 @@ pub fn create_session(
         file_loader,
         target_override,
         rustc_version_str().unwrap_or("unknown"),
+        ice_file,
     );
 
     codegen_backend.init(&sess);
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index 6522e449386..7c701fd4fe1 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -956,11 +956,11 @@ pub trait LintContext: Sized {
                     db.span_note(glob_reexport_span, format!("the name `{}` in the {} namespace is supposed to be publicly re-exported here", name, namespace));
                     db.span_note(private_item_span, "but the private item here shadows it".to_owned());
                 }
-                BuiltinLintDiagnostics::UnusedQualifications { path_span, unqualified_path } => {
+                BuiltinLintDiagnostics::UnusedQualifications { removal_span } => {
                     db.span_suggestion_verbose(
-                        path_span,
-                        "replace it with the unqualified path",
-                        unqualified_path,
+                        removal_span,
+                        "remove the unnecessary path segments",
+                        "",
                         Applicability::MachineApplicable
                     );
                 }
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index c9ee2da6fdf..0c80141a756 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -978,6 +978,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     /// Returns `true` if the lint's feature is enabled.
     // FIXME only emit this once for each attribute, instead of repeating it 4 times for
     // pre-expansion lints, post-expansion lints, `shallow_lint_levels_on` and `lint_expectations`.
+    #[track_caller]
     fn check_gated_lint(&self, lint_id: LintId, span: Span) -> bool {
         if let Some(feature) = lint_id.lint.feature_gate {
             if !self.sess.features_untracked().enabled(feature) {
@@ -1015,6 +1016,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub(crate) fn struct_lint(
         &self,
         lint: &'static Lint,
@@ -1028,6 +1030,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         struct_lint_level(self.sess, lint, level, src, span, msg, decorate)
     }
 
+    #[track_caller]
     pub fn emit_spanned_lint(
         &self,
         lint: &'static Lint,
@@ -1040,6 +1043,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         });
     }
 
+    #[track_caller]
     pub fn emit_lint(&self, lint: &'static Lint, decorate: impl for<'a> DecorateLint<'a, ()>) {
         let (level, src) = self.lint_level(lint);
         struct_lint_level(self.sess, lint, level, src, None, decorate.msg(), |lint| {
diff --git a/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs b/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs
index d5f0290767a..79b0b32bef2 100644
--- a/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs
+++ b/compiler/rustc_lint/src/opaque_hidden_inferred_bound.rs
@@ -117,7 +117,7 @@ impl<'tcx> LateLintPass<'tcx> for OpaqueHiddenInferredBound {
             for (assoc_pred, assoc_pred_span) in cx
                 .tcx
                 .explicit_item_bounds(proj.projection_ty.def_id)
-                .arg_iter_copied(cx.tcx, &proj.projection_ty.args)
+                .iter_instantiated_copied(cx.tcx, &proj.projection_ty.args)
             {
                 let assoc_pred = assoc_pred.fold_with(proj_replacer);
                 let Ok(assoc_pred) = traits::fully_normalize(
diff --git a/compiler/rustc_lint_defs/src/lib.rs b/compiler/rustc_lint_defs/src/lib.rs
index f6ffd46b1fe..10ebe29dfce 100644
--- a/compiler/rustc_lint_defs/src/lib.rs
+++ b/compiler/rustc_lint_defs/src/lib.rs
@@ -551,10 +551,8 @@ pub enum BuiltinLintDiagnostics {
         private_item_span: Span,
     },
     UnusedQualifications {
-        /// The span of the unnecessarily-qualified path.
-        path_span: Span,
-        /// The replacement unqualified path.
-        unqualified_path: Ident,
+        /// The span of the unnecessarily-qualified path to remove.
+        removal_span: Span,
     },
 }
 
diff --git a/compiler/rustc_metadata/src/foreign_modules.rs b/compiler/rustc_metadata/src/foreign_modules.rs
index d1c2f3104d0..154eb684f11 100644
--- a/compiler/rustc_metadata/src/foreign_modules.rs
+++ b/compiler/rustc_metadata/src/foreign_modules.rs
@@ -1,19 +1,28 @@
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
+use rustc_hir::def_id::DefId;
+use rustc_middle::query::LocalCrate;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::cstore::ForeignModule;
 
-pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<ForeignModule> {
-    let mut modules = Vec::new();
+pub(crate) fn collect(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> FxIndexMap<DefId, ForeignModule> {
+    let mut modules = FxIndexMap::default();
+
+    // We need to collect all the `ForeignMod`, even if they are empty.
     for id in tcx.hir().items() {
         if !matches!(tcx.def_kind(id.owner_id), DefKind::ForeignMod) {
             continue;
         }
+
+        let def_id = id.owner_id.to_def_id();
         let item = tcx.hir().item(id);
-        if let hir::ItemKind::ForeignMod { items, .. } = item.kind {
+
+        if let hir::ItemKind::ForeignMod { abi, items } = item.kind {
             let foreign_items = items.iter().map(|it| it.id.owner_id.to_def_id()).collect();
-            modules.push(ForeignModule { foreign_items, def_id: id.owner_id.to_def_id() });
+            modules.insert(def_id, ForeignModule { def_id, abi, foreign_items });
         }
     }
+
     modules
 }
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index 9e0bf81d58d..ca5043cc263 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -1,15 +1,17 @@
 use rustc_ast::{NestedMetaItem, CRATE_NODE_ID};
 use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashSet;
-use rustc_hir as hir;
-use rustc_hir::def::DefKind;
+use rustc_middle::query::LocalCrate;
 use rustc_middle::ty::{List, ParamEnv, ParamEnvAnd, Ty, TyCtxt};
 use rustc_session::config::CrateType;
-use rustc_session::cstore::{DllCallingConvention, DllImport, NativeLib, PeImportNameType};
+use rustc_session::cstore::{
+    DllCallingConvention, DllImport, ForeignModule, NativeLib, PeImportNameType,
+};
 use rustc_session::parse::feature_err;
 use rustc_session::search_paths::PathKind;
 use rustc_session::utils::NativeLibKind;
 use rustc_session::Session;
+use rustc_span::def_id::{DefId, LOCAL_CRATE};
 use rustc_span::symbol::{sym, Symbol};
 use rustc_target::spec::abi::Abi;
 
@@ -66,10 +68,12 @@ fn find_bundled_library(
     None
 }
 
-pub(crate) fn collect(tcx: TyCtxt<'_>) -> Vec<NativeLib> {
+pub(crate) fn collect(tcx: TyCtxt<'_>, LocalCrate: LocalCrate) -> Vec<NativeLib> {
     let mut collector = Collector { tcx, libs: Vec::new() };
-    for id in tcx.hir().items() {
-        collector.process_item(id);
+    if tcx.sess.opts.unstable_opts.link_directives {
+        for module in tcx.foreign_modules(LOCAL_CRATE).values() {
+            collector.process_module(module);
+        }
     }
     collector.process_command_line();
     collector.libs
@@ -88,29 +92,20 @@ struct Collector<'tcx> {
 }
 
 impl<'tcx> Collector<'tcx> {
-    fn process_item(&mut self, id: rustc_hir::ItemId) {
-        if !matches!(self.tcx.def_kind(id.owner_id), DefKind::ForeignMod) {
-            return;
-        }
+    fn process_module(&mut self, module: &ForeignModule) {
+        let ForeignModule { def_id, abi, ref foreign_items } = *module;
+        let def_id = def_id.expect_local();
 
-        let it = self.tcx.hir().item(id);
-        let hir::ItemKind::ForeignMod { abi, items: foreign_mod_items } = it.kind else {
-            return;
-        };
+        let sess = self.tcx.sess;
 
         if matches!(abi, Abi::Rust | Abi::RustIntrinsic | Abi::PlatformIntrinsic) {
             return;
         }
 
         // Process all of the #[link(..)]-style arguments
-        let sess = self.tcx.sess;
         let features = self.tcx.features();
 
-        if !sess.opts.unstable_opts.link_directives {
-            return;
-        }
-
-        for m in self.tcx.hir().attrs(it.hir_id()).iter().filter(|a| a.has_name(sym::link)) {
+        for m in self.tcx.get_attrs(def_id, sym::link) {
             let Some(items) = m.meta_item_list() else {
                 continue;
             };
@@ -340,9 +335,9 @@ impl<'tcx> Collector<'tcx> {
                     if name.as_str().contains('\0') {
                         sess.emit_err(errors::RawDylibNoNul { span: name_span });
                     }
-                    foreign_mod_items
+                    foreign_items
                         .iter()
-                        .map(|child_item| {
+                        .map(|&child_item| {
                             self.build_dll_import(
                                 abi,
                                 import_name_type.map(|(import_name_type, _)| import_name_type),
@@ -352,21 +347,12 @@ impl<'tcx> Collector<'tcx> {
                         .collect()
                 }
                 _ => {
-                    for child_item in foreign_mod_items {
-                        if self.tcx.def_kind(child_item.id.owner_id).has_codegen_attrs()
-                            && self
-                                .tcx
-                                .codegen_fn_attrs(child_item.id.owner_id)
-                                .link_ordinal
-                                .is_some()
+                    for &child_item in foreign_items {
+                        if self.tcx.def_kind(child_item).has_codegen_attrs()
+                            && self.tcx.codegen_fn_attrs(child_item).link_ordinal.is_some()
                         {
-                            let link_ordinal_attr = self
-                                .tcx
-                                .hir()
-                                .attrs(child_item.id.owner_id.into())
-                                .iter()
-                                .find(|a| a.has_name(sym::link_ordinal))
-                                .unwrap();
+                            let link_ordinal_attr =
+                                self.tcx.get_attr(child_item, sym::link_ordinal).unwrap();
                             sess.emit_err(errors::LinkOrdinalRawDylib {
                                 span: link_ordinal_attr.span,
                             });
@@ -384,7 +370,7 @@ impl<'tcx> Collector<'tcx> {
                 filename,
                 kind,
                 cfg,
-                foreign_module: Some(it.owner_id.to_def_id()),
+                foreign_module: Some(def_id.to_def_id()),
                 verbatim,
                 dll_imports,
             });
@@ -476,10 +462,10 @@ impl<'tcx> Collector<'tcx> {
         }
     }
 
-    fn i686_arg_list_size(&self, item: &hir::ForeignItemRef) -> usize {
+    fn i686_arg_list_size(&self, item: DefId) -> usize {
         let argument_types: &List<Ty<'_>> = self.tcx.erase_late_bound_regions(
             self.tcx
-                .type_of(item.id.owner_id)
+                .type_of(item)
                 .instantiate_identity()
                 .fn_sig(self.tcx)
                 .inputs()
@@ -505,8 +491,10 @@ impl<'tcx> Collector<'tcx> {
         &self,
         abi: Abi,
         import_name_type: Option<PeImportNameType>,
-        item: &hir::ForeignItemRef,
+        item: DefId,
     ) -> DllImport {
+        let span = self.tcx.def_span(item);
+
         let calling_convention = if self.tcx.sess.target.arch == "x86" {
             match abi {
                 Abi::C { .. } | Abi::Cdecl { .. } => DllCallingConvention::C,
@@ -520,29 +508,29 @@ impl<'tcx> Collector<'tcx> {
                     DllCallingConvention::Vectorcall(self.i686_arg_list_size(item))
                 }
                 _ => {
-                    self.tcx.sess.emit_fatal(errors::UnsupportedAbiI686 { span: item.span });
+                    self.tcx.sess.emit_fatal(errors::UnsupportedAbiI686 { span });
                 }
             }
         } else {
             match abi {
                 Abi::C { .. } | Abi::Win64 { .. } | Abi::System { .. } => DllCallingConvention::C,
                 _ => {
-                    self.tcx.sess.emit_fatal(errors::UnsupportedAbi { span: item.span });
+                    self.tcx.sess.emit_fatal(errors::UnsupportedAbi { span });
                 }
             }
         };
 
-        let codegen_fn_attrs = self.tcx.codegen_fn_attrs(item.id.owner_id);
+        let codegen_fn_attrs = self.tcx.codegen_fn_attrs(item);
         let import_name_type = codegen_fn_attrs
             .link_ordinal
             .map_or(import_name_type, |ord| Some(PeImportNameType::Ordinal(ord)));
 
         DllImport {
-            name: codegen_fn_attrs.link_name.unwrap_or(item.ident.name),
+            name: codegen_fn_attrs.link_name.unwrap_or(self.tcx.item_name(item)),
             import_name_type,
             calling_convention,
-            span: item.span,
-            is_fn: self.tcx.def_kind(item.id.owner_id).is_fn_like(),
+            span,
+            is_fn: self.tcx.def_kind(item).is_fn_like(),
         }
     }
 }
diff --git a/compiler/rustc_metadata/src/rmeta/decoder.rs b/compiler/rustc_metadata/src/rmeta/decoder.rs
index 8fa1d365728..9e67bb655d4 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder.rs
@@ -34,7 +34,7 @@ use rustc_session::cstore::{
 use rustc_session::Session;
 use rustc_span::hygiene::ExpnIndex;
 use rustc_span::symbol::{kw, Ident, Symbol};
-use rustc_span::{self, BytePos, ExpnId, Pos, Span, SyntaxContext, DUMMY_SP};
+use rustc_span::{self, BytePos, ExpnId, Pos, Span, SpanData, SyntaxContext, DUMMY_SP};
 
 use proc_macro::bridge::client::ProcMacro;
 use std::iter::TrustedLen;
@@ -513,11 +513,26 @@ impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for ExpnId {
 
 impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
     fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> Span {
+        let mode = SpanEncodingMode::decode(decoder);
+        let data = match mode {
+            SpanEncodingMode::Direct => SpanData::decode(decoder),
+            SpanEncodingMode::Shorthand(position) => decoder.with_position(position, |decoder| {
+                let mode = SpanEncodingMode::decode(decoder);
+                debug_assert!(matches!(mode, SpanEncodingMode::Direct));
+                SpanData::decode(decoder)
+            }),
+        };
+        Span::new(data.lo, data.hi, data.ctxt, data.parent)
+    }
+}
+
+impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for SpanData {
+    fn decode(decoder: &mut DecodeContext<'a, 'tcx>) -> SpanData {
         let ctxt = SyntaxContext::decode(decoder);
         let tag = u8::decode(decoder);
 
         if tag == TAG_PARTIAL_SPAN {
-            return DUMMY_SP.with_ctxt(ctxt);
+            return DUMMY_SP.with_ctxt(ctxt).data();
         }
 
         debug_assert!(tag == TAG_VALID_SPAN_LOCAL || tag == TAG_VALID_SPAN_FOREIGN);
@@ -612,7 +627,7 @@ impl<'a, 'tcx> Decodable<DecodeContext<'a, 'tcx>> for Span {
         let hi = hi + source_file.translated_source_file.start_pos;
 
         // Do not try to decode parent for foreign spans.
-        Span::new(lo, hi, ctxt, None)
+        SpanData { lo, hi, ctxt, parent: None }
     }
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 848535fb395..a8815ee0908 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -403,10 +403,8 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
                         .contains(&id)
                 })
         },
-        native_libraries: |tcx, LocalCrate| native_libs::collect(tcx),
-        foreign_modules: |tcx, LocalCrate| {
-            foreign_modules::collect(tcx).into_iter().map(|m| (m.def_id, m)).collect()
-        },
+        native_libraries: native_libs::collect,
+        foreign_modules: foreign_modules::collect,
 
         // Returns a map from a sufficiently visible external item (i.e., an
         // external item that is visible from at least one local module) to a
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 2785732727f..ac86110f2bd 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -37,7 +37,7 @@ use rustc_session::config::{CrateType, OptLevel};
 use rustc_session::cstore::{ForeignModule, LinkagePreference, NativeLib};
 use rustc_span::hygiene::{ExpnIndex, HygieneEncodeContext, MacroKind};
 use rustc_span::symbol::{sym, Symbol};
-use rustc_span::{self, ExternalSource, FileName, SourceFile, Span, SyntaxContext};
+use rustc_span::{self, ExternalSource, FileName, SourceFile, Span, SpanData, SyntaxContext};
 use std::borrow::Borrow;
 use std::collections::hash_map::Entry;
 use std::hash::Hash;
@@ -53,6 +53,7 @@ pub(super) struct EncodeContext<'a, 'tcx> {
     tables: TableBuilders,
 
     lazy_state: LazyState,
+    span_shorthands: FxHashMap<Span, usize>,
     type_shorthands: FxHashMap<Ty<'tcx>, usize>,
     predicate_shorthands: FxHashMap<ty::PredicateKind<'tcx>, usize>,
 
@@ -177,8 +178,20 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnId {
 
 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
     fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
-        let span = self.data();
+        match s.span_shorthands.entry(*self) {
+            Entry::Occupied(o) => SpanEncodingMode::Shorthand(*o.get()).encode(s),
+            Entry::Vacant(v) => {
+                let position = s.opaque.position();
+                v.insert(position);
+                SpanEncodingMode::Direct.encode(s);
+                self.data().encode(s);
+            }
+        }
+    }
+}
 
+impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for SpanData {
+    fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) {
         // Don't serialize any `SyntaxContext`s from a proc-macro crate,
         // since we don't load proc-macro dependencies during serialization.
         // This means that any hygiene information from macros used *within*
@@ -213,7 +226,7 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
         if s.is_proc_macro {
             SyntaxContext::root().encode(s);
         } else {
-            span.ctxt.encode(s);
+            self.ctxt.encode(s);
         }
 
         if self.is_dummy() {
@@ -221,18 +234,18 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
         }
 
         // The Span infrastructure should make sure that this invariant holds:
-        debug_assert!(span.lo <= span.hi);
+        debug_assert!(self.lo <= self.hi);
 
-        if !s.source_file_cache.0.contains(span.lo) {
+        if !s.source_file_cache.0.contains(self.lo) {
             let source_map = s.tcx.sess.source_map();
-            let source_file_index = source_map.lookup_source_file_idx(span.lo);
+            let source_file_index = source_map.lookup_source_file_idx(self.lo);
             s.source_file_cache =
                 (source_map.files()[source_file_index].clone(), source_file_index);
         }
         let (ref source_file, source_file_index) = s.source_file_cache;
-        debug_assert!(source_file.contains(span.lo));
+        debug_assert!(source_file.contains(self.lo));
 
-        if !source_file.contains(span.hi) {
+        if !source_file.contains(self.hi) {
             // Unfortunately, macro expansion still sometimes generates Spans
             // that malformed in this way.
             return TAG_PARTIAL_SPAN.encode(s);
@@ -286,11 +299,11 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
 
         // Encode the start position relative to the file start, so we profit more from the
         // variable-length integer encoding.
-        let lo = span.lo - source_file.start_pos;
+        let lo = self.lo - source_file.start_pos;
 
         // Encode length which is usually less than span.hi and profits more
         // from the variable-length integer encoding that we use.
-        let len = span.hi - span.lo;
+        let len = self.hi - self.lo;
 
         tag.encode(s);
         lo.encode(s);
@@ -2182,6 +2195,7 @@ fn encode_metadata_impl(tcx: TyCtxt<'_>, path: &Path) {
         feat: tcx.features(),
         tables: Default::default(),
         lazy_state: LazyState::NoNode,
+        span_shorthands: Default::default(),
         type_shorthands: Default::default(),
         predicate_shorthands: Default::default(),
         source_file_cache,
diff --git a/compiler/rustc_metadata/src/rmeta/mod.rs b/compiler/rustc_metadata/src/rmeta/mod.rs
index f6087fbe8f6..0bc16fc64ff 100644
--- a/compiler/rustc_metadata/src/rmeta/mod.rs
+++ b/compiler/rustc_metadata/src/rmeta/mod.rs
@@ -66,6 +66,12 @@ const METADATA_VERSION: u8 = 8;
 /// unsigned integer, and further followed by the rustc version string.
 pub const METADATA_HEADER: &[u8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_VERSION];
 
+#[derive(Encodable, Decodable)]
+enum SpanEncodingMode {
+    Shorthand(usize),
+    Direct,
+}
+
 /// A value of type T referred to by its absolute position
 /// in the metadata, and which can be decoded lazily.
 ///
diff --git a/compiler/rustc_middle/src/lint.rs b/compiler/rustc_middle/src/lint.rs
index 20230217afc..6ce1ad8f43e 100644
--- a/compiler/rustc_middle/src/lint.rs
+++ b/compiler/rustc_middle/src/lint.rs
@@ -278,6 +278,7 @@ pub fn explain_lint_level_source(
 ///     //          ^^^^^^^^^^^^^^^^^^^^^ returns `&mut DiagnosticBuilder` by default
 /// )
 /// ```
+#[track_caller]
 pub fn struct_lint_level(
     sess: &Session,
     lint: &'static Lint,
@@ -291,6 +292,7 @@ pub fn struct_lint_level(
 ) {
     // Avoid codegen bloat from monomorphization by immediately doing dyn dispatch of `decorate` to
     // the "real" work.
+    #[track_caller]
     fn struct_lint_level_impl(
         sess: &Session,
         lint: &'static Lint,
diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
index c4601a1fb41..02fd6ed7ba6 100644
--- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
+++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs
@@ -100,6 +100,8 @@ bitflags! {
         const REALLOCATOR               = 1 << 18;
         /// `#[rustc_allocator_zeroed]`: a hint to LLVM that the function only allocates zeroed memory.
         const ALLOCATOR_ZEROED          = 1 << 19;
+        /// `#[no_builtins]`: indicates that disable implicit builtin knowledge of functions for the function.
+        const NO_BUILTINS               = 1 << 20;
     }
 }
 
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 16addc2dc1e..f4133dfbc95 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -56,6 +56,8 @@ impl<'tcx> MonoItem<'tcx> {
         }
     }
 
+    // Note: if you change how item size estimates work, you might need to
+    // change NON_INCR_MIN_CGU_SIZE as well.
     pub fn size_estimate(&self, tcx: TyCtxt<'tcx>) -> usize {
         match *self {
             MonoItem::Fn(instance) => {
@@ -248,8 +250,14 @@ pub struct CodegenUnit<'tcx> {
 /// Auxiliary info about a `MonoItem`.
 #[derive(Copy, Clone, PartialEq, Debug, HashStable)]
 pub struct MonoItemData {
+    /// A cached copy of the result of `MonoItem::instantiation_mode`, where
+    /// `GloballyShared` maps to `false` and `LocalCopy` maps to `true`.
+    pub inlined: bool,
+
     pub linkage: Linkage,
     pub visibility: Visibility,
+
+    /// A cached copy of the result of `MonoItem::size_estimate`.
     pub size_estimate: usize,
 }
 
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index c304245ca39..062adc9ec54 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1579,7 +1579,7 @@ rustc_queries! {
     }
 
     /// Returns a list of all `extern` blocks of a crate.
-    query foreign_modules(_: CrateNum) -> &'tcx FxHashMap<DefId, ForeignModule> {
+    query foreign_modules(_: CrateNum) -> &'tcx FxIndexMap<DefId, ForeignModule> {
         arena_cache
         desc { "looking up the foreign modules of a linked crate" }
         separate_provide_extern
diff --git a/compiler/rustc_middle/src/ty/consts.rs b/compiler/rustc_middle/src/ty/consts.rs
index bf9f5846ed9..4ef70107f19 100644
--- a/compiler/rustc_middle/src/ty/consts.rs
+++ b/compiler/rustc_middle/src/ty/consts.rs
@@ -294,6 +294,14 @@ impl<'tcx> Const<'tcx> {
         Self::from_bits(tcx, n as u128, ParamEnv::empty().and(tcx.types.usize))
     }
 
+    /// Attempts to convert to a `ValTree`
+    pub fn try_to_valtree(self) -> Option<ty::ValTree<'tcx>> {
+        match self.kind() {
+            ty::ConstKind::Value(valtree) => Some(valtree),
+            _ => None,
+        }
+    }
+
     #[inline]
     /// Attempts to evaluate the given constant to bits. Can fail to evaluate in the presence of
     /// generics (or erroneous code) or if the value can't be represented as bits (e.g. because it
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 8bb13edbe95..1a23fa80210 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1860,6 +1860,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Emit a lint at `span` from a lint struct (some type that implements `DecorateLint`,
     /// typically generated by `#[derive(LintDiagnostic)]`).
+    #[track_caller]
     pub fn emit_spanned_lint(
         self,
         lint: &'static Lint,
@@ -1880,6 +1881,7 @@ impl<'tcx> TyCtxt<'tcx> {
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_span_lint_hir(
         self,
         lint: &'static Lint,
@@ -1896,6 +1898,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Emit a lint from a lint struct (some type that implements `DecorateLint`, typically
     /// generated by `#[derive(LintDiagnostic)]`).
+    #[track_caller]
     pub fn emit_lint(
         self,
         lint: &'static Lint,
@@ -1911,6 +1914,7 @@ impl<'tcx> TyCtxt<'tcx> {
     ///
     /// [`struct_lint_level`]: rustc_middle::lint::struct_lint_level#decorate-signature
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_lint_node(
         self,
         lint: &'static Lint,
diff --git a/compiler/rustc_middle/src/ty/generic_args.rs b/compiler/rustc_middle/src/ty/generic_args.rs
index 12af8456494..97dab5cb47e 100644
--- a/compiler/rustc_middle/src/ty/generic_args.rs
+++ b/compiler/rustc_middle/src/ty/generic_args.rs
@@ -610,8 +610,12 @@ impl<'tcx, 's, I: IntoIterator> EarlyBinder<I>
 where
     I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
-    pub fn arg_iter(self, tcx: TyCtxt<'tcx>, args: &'s [GenericArg<'tcx>]) -> ArgIter<'s, 'tcx, I> {
-        ArgIter { it: self.value.into_iter(), tcx, args }
+    pub fn iter_instantiated(
+        self,
+        tcx: TyCtxt<'tcx>,
+        args: &'s [GenericArg<'tcx>],
+    ) -> IterInstantiated<'s, 'tcx, I> {
+        IterInstantiated { it: self.value.into_iter(), tcx, args }
     }
 
     /// Similar to [`instantiate_identity`](EarlyBinder::instantiate_identity),
@@ -621,13 +625,13 @@ where
     }
 }
 
-pub struct ArgIter<'s, 'tcx, I: IntoIterator> {
+pub struct IterInstantiated<'s, 'tcx, I: IntoIterator> {
     it: I::IntoIter,
     tcx: TyCtxt<'tcx>,
     args: &'s [GenericArg<'tcx>],
 }
 
-impl<'tcx, I: IntoIterator> Iterator for ArgIter<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> Iterator for IterInstantiated<'_, 'tcx, I>
 where
     I::Item: TypeFoldable<TyCtxt<'tcx>>,
 {
@@ -642,7 +646,7 @@ where
     }
 }
 
-impl<'tcx, I: IntoIterator> DoubleEndedIterator for ArgIter<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> DoubleEndedIterator for IterInstantiated<'_, 'tcx, I>
 where
     I::IntoIter: DoubleEndedIterator,
     I::Item: TypeFoldable<TyCtxt<'tcx>>,
@@ -652,7 +656,7 @@ where
     }
 }
 
-impl<'tcx, I: IntoIterator> ExactSizeIterator for ArgIter<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> ExactSizeIterator for IterInstantiated<'_, 'tcx, I>
 where
     I::IntoIter: ExactSizeIterator,
     I::Item: TypeFoldable<TyCtxt<'tcx>>,
@@ -664,12 +668,12 @@ where
     I::Item: Deref,
     <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
 {
-    pub fn arg_iter_copied(
+    pub fn iter_instantiated_copied(
         self,
         tcx: TyCtxt<'tcx>,
         args: &'s [GenericArg<'tcx>],
-    ) -> ArgIterCopied<'s, 'tcx, I> {
-        ArgIterCopied { it: self.value.into_iter(), tcx, args }
+    ) -> IterInstantiatedCopied<'s, 'tcx, I> {
+        IterInstantiatedCopied { it: self.value.into_iter(), tcx, args }
     }
 
     /// Similar to [`instantiate_identity`](EarlyBinder::instantiate_identity),
@@ -681,13 +685,13 @@ where
     }
 }
 
-pub struct ArgIterCopied<'a, 'tcx, I: IntoIterator> {
+pub struct IterInstantiatedCopied<'a, 'tcx, I: IntoIterator> {
     it: I::IntoIter,
     tcx: TyCtxt<'tcx>,
     args: &'a [GenericArg<'tcx>],
 }
 
-impl<'tcx, I: IntoIterator> Iterator for ArgIterCopied<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> Iterator for IterInstantiatedCopied<'_, 'tcx, I>
 where
     I::Item: Deref,
     <I::Item as Deref>::Target: Copy + TypeFoldable<TyCtxt<'tcx>>,
@@ -703,7 +707,7 @@ where
     }
 }
 
-impl<'tcx, I: IntoIterator> DoubleEndedIterator for ArgIterCopied<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> DoubleEndedIterator for IterInstantiatedCopied<'_, 'tcx, I>
 where
     I::IntoIter: DoubleEndedIterator,
     I::Item: Deref,
@@ -716,7 +720,7 @@ where
     }
 }
 
-impl<'tcx, I: IntoIterator> ExactSizeIterator for ArgIterCopied<'_, 'tcx, I>
+impl<'tcx, I: IntoIterator> ExactSizeIterator for IterInstantiatedCopied<'_, 'tcx, I>
 where
     I::IntoIter: ExactSizeIterator,
     I::Item: Deref,
diff --git a/compiler/rustc_middle/src/ty/generics.rs b/compiler/rustc_middle/src/ty/generics.rs
index 338590717d0..70a35f137d8 100644
--- a/compiler/rustc_middle/src/ty/generics.rs
+++ b/compiler/rustc_middle/src/ty/generics.rs
@@ -347,7 +347,7 @@ impl<'tcx> GenericPredicates<'tcx> {
         tcx: TyCtxt<'tcx>,
         args: GenericArgsRef<'tcx>,
     ) -> impl Iterator<Item = (Clause<'tcx>, Span)> + DoubleEndedIterator + ExactSizeIterator {
-        EarlyBinder::bind(self.predicates).arg_iter_copied(tcx, args)
+        EarlyBinder::bind(self.predicates).iter_instantiated_copied(tcx, args)
     }
 
     #[instrument(level = "debug", skip(self, tcx))]
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index 3591acdea56..e5633223464 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -928,7 +928,7 @@ pub trait PrettyPrinter<'tcx>:
         let mut is_sized = false;
         let mut lifetimes = SmallVec::<[ty::Region<'tcx>; 1]>::new();
 
-        for (predicate, _) in bounds.arg_iter_copied(tcx, args) {
+        for (predicate, _) in bounds.iter_instantiated_copied(tcx, args) {
             let bound_predicate = predicate.kind();
 
             match bound_predicate.skip_binder() {
@@ -1932,7 +1932,7 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
     fn path_crate(mut self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
         self.empty_path = true;
         if cnum == LOCAL_CRATE {
-            if self.tcx.sess.rust_2018() {
+            if self.tcx.sess.at_least_rust_2018() {
                 // We add the `crate::` keyword on Rust 2018, only when desired.
                 if SHOULD_PREFIX_WITH_CRATE.with(|flag| flag.get()) {
                     write!(self, "{}", kw::Crate)?;
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index cdb0b2240a4..f9c1ca9a8b1 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -15,7 +15,6 @@ use hir::def::DefKind;
 use polonius_engine::Atom;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::intern::Interned;
-use rustc_error_messages::DiagnosticMessage;
 use rustc_errors::{DiagnosticArgValue, ErrorGuaranteed, IntoDiagnosticArg, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
@@ -1991,7 +1990,7 @@ impl<'tcx> Ty<'tcx> {
     pub fn new_error_with_message<S: Into<MultiSpan>>(
         tcx: TyCtxt<'tcx>,
         span: S,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<String>,
     ) -> Ty<'tcx> {
         let reported = tcx.sess.delay_span_bug(span, msg);
         Ty::new(tcx, Error(reported))
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index b4852ab8881..553b76cad4e 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -19,7 +19,7 @@ use rustc_index::bit_set::GrowableBitSet;
 use rustc_macros::HashStable;
 use rustc_session::Limit;
 use rustc_span::sym;
-use rustc_target::abi::{Integer, IntegerType, Size, TargetDataLayout};
+use rustc_target::abi::{Integer, IntegerType, Size};
 use rustc_target::spec::abi::Abi;
 use smallvec::SmallVec;
 use std::{fmt, iter};
@@ -1085,7 +1085,7 @@ impl<'tcx> Ty<'tcx> {
     #[inline]
     pub fn needs_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
         // Avoid querying in simple cases.
-        match needs_drop_components(self, &tcx.data_layout) {
+        match needs_drop_components(tcx, self) {
             Err(AlwaysRequiresDrop) => true,
             Ok(components) => {
                 let query_ty = match *components {
@@ -1118,7 +1118,7 @@ impl<'tcx> Ty<'tcx> {
     #[inline]
     pub fn has_significant_drop(self, tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> bool {
         // Avoid querying in simple cases.
-        match needs_drop_components(self, &tcx.data_layout) {
+        match needs_drop_components(tcx, self) {
             Err(AlwaysRequiresDrop) => true,
             Ok(components) => {
                 let query_ty = match *components {
@@ -1278,10 +1278,10 @@ impl<'tcx> ExplicitSelf<'tcx> {
 /// *any* of the returned types need drop. Returns `Err(AlwaysRequiresDrop)` if
 /// this type always needs drop.
 pub fn needs_drop_components<'tcx>(
+    tcx: TyCtxt<'tcx>,
     ty: Ty<'tcx>,
-    target_layout: &TargetDataLayout,
 ) -> Result<SmallVec<[Ty<'tcx>; 2]>, AlwaysRequiresDrop> {
-    match ty.kind() {
+    match *ty.kind() {
         ty::Infer(ty::FreshIntTy(_))
         | ty::Infer(ty::FreshFloatTy(_))
         | ty::Bool
@@ -1303,11 +1303,11 @@ pub fn needs_drop_components<'tcx>(
 
         ty::Dynamic(..) | ty::Error(_) => Err(AlwaysRequiresDrop),
 
-        ty::Slice(ty) => needs_drop_components(*ty, target_layout),
+        ty::Slice(ty) => needs_drop_components(tcx, ty),
         ty::Array(elem_ty, size) => {
-            match needs_drop_components(*elem_ty, target_layout) {
+            match needs_drop_components(tcx, elem_ty) {
                 Ok(v) if v.is_empty() => Ok(v),
-                res => match size.try_to_bits(target_layout.pointer_size) {
+                res => match size.try_to_target_usize(tcx) {
                     // Arrays of size zero don't need drop, even if their element
                     // type does.
                     Some(0) => Ok(SmallVec::new()),
@@ -1321,7 +1321,7 @@ pub fn needs_drop_components<'tcx>(
         }
         // If any field needs drop, then the whole tuple does.
         ty::Tuple(fields) => fields.iter().try_fold(SmallVec::new(), move |mut acc, elem| {
-            acc.extend(needs_drop_components(elem, target_layout)?);
+            acc.extend(needs_drop_components(tcx, elem)?);
             Ok(acc)
         }),
 
diff --git a/compiler/rustc_mir_build/src/build/expr/as_place.rs b/compiler/rustc_mir_build/src/build/expr/as_place.rs
index c122230b841..7756d5d4879 100644
--- a/compiler/rustc_mir_build/src/build/expr/as_place.rs
+++ b/compiler/rustc_mir_build/src/build/expr/as_place.rs
@@ -730,5 +730,5 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
 /// Precise capture is enabled if user is using Rust Edition 2021 or higher.
 fn enable_precise_capture(closure_span: Span) -> bool {
-    closure_span.rust_2021()
+    closure_span.at_least_rust_2021()
 }
diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index 54096abb2e0..71aef53192f 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -248,7 +248,8 @@ where
         }
         let size_estimate = mono_item.size_estimate(cx.tcx);
 
-        cgu.items_mut().insert(mono_item, MonoItemData { linkage, visibility, size_estimate });
+        cgu.items_mut()
+            .insert(mono_item, MonoItemData { inlined: false, linkage, visibility, size_estimate });
 
         // Get all inlined items that are reachable from `mono_item` without
         // going via another root item. This includes drop-glue, functions from
@@ -263,6 +264,7 @@ where
         for inlined_item in reachable_inlined_items {
             // This is a CGU-private copy.
             cgu.items_mut().entry(inlined_item).or_insert_with(|| MonoItemData {
+                inlined: true,
                 linkage: Linkage::Internal,
                 visibility: Visibility::Default,
                 size_estimate: inlined_item.size_estimate(cx.tcx),
@@ -316,6 +318,60 @@ fn merge_codegen_units<'tcx>(
     let mut cgu_contents: FxHashMap<Symbol, Vec<Symbol>> =
         codegen_units.iter().map(|cgu| (cgu.name(), vec![cgu.name()])).collect();
 
+    // If N is the maximum number of CGUs, and the CGUs are sorted from largest
+    // to smallest, we repeatedly find which CGU in codegen_units[N..] has the
+    // greatest overlap of inlined items with codegen_units[N-1], merge that
+    // CGU into codegen_units[N-1], then re-sort by size and repeat.
+    //
+    // We use inlined item overlap to guide this merging because it minimizes
+    // duplication of inlined items, which makes LLVM be faster and generate
+    // better and smaller machine code.
+    //
+    // Why merge into codegen_units[N-1]? We want CGUs to have similar sizes,
+    // which means we don't want codegen_units[0..N] (the already big ones)
+    // getting any bigger, if we can avoid it. When we have more than N CGUs
+    // then at least one of the biggest N will have to grow. codegen_units[N-1]
+    // is the smallest of those, and so has the most room to grow.
+    let max_codegen_units = cx.tcx.sess.codegen_units().as_usize();
+    while codegen_units.len() > max_codegen_units {
+        // Sort small CGUs to the back.
+        codegen_units.sort_by_key(|cgu| cmp::Reverse(cgu.size_estimate()));
+
+        let cgu_dst = &codegen_units[max_codegen_units - 1];
+
+        // Find the CGU that overlaps the most with `cgu_dst`. In the case of a
+        // tie, favour the earlier (bigger) CGU.
+        let mut max_overlap = 0;
+        let mut max_overlap_i = max_codegen_units;
+        for (i, cgu_src) in codegen_units.iter().enumerate().skip(max_codegen_units) {
+            if cgu_src.size_estimate() <= max_overlap {
+                // None of the remaining overlaps can exceed `max_overlap`, so
+                // stop looking.
+                break;
+            }
+
+            let overlap = compute_inlined_overlap(cgu_dst, cgu_src);
+            if overlap > max_overlap {
+                max_overlap = overlap;
+                max_overlap_i = i;
+            }
+        }
+
+        let mut cgu_src = codegen_units.swap_remove(max_overlap_i);
+        let cgu_dst = &mut codegen_units[max_codegen_units - 1];
+
+        // Move the items from `cgu_src` to `cgu_dst`. Some of them may be
+        // duplicate inlined items, in which case the destination CGU is
+        // unaffected. Recalculate size estimates afterwards.
+        cgu_dst.items_mut().extend(cgu_src.items_mut().drain());
+        cgu_dst.compute_size_estimate();
+
+        // Record that `cgu_dst` now contains all the stuff that was in
+        // `cgu_src` before.
+        let mut consumed_cgu_names = cgu_contents.remove(&cgu_src.name()).unwrap();
+        cgu_contents.get_mut(&cgu_dst.name()).unwrap().append(&mut consumed_cgu_names);
+    }
+
     // Having multiple CGUs can drastically speed up compilation. But for
     // non-incremental builds, tiny CGUs slow down compilation *and* result in
     // worse generated code. So we don't allow CGUs smaller than this (unless
@@ -323,24 +379,22 @@ fn merge_codegen_units<'tcx>(
     // common in larger programs, so this isn't all that large.
     const NON_INCR_MIN_CGU_SIZE: usize = 1800;
 
-    // Repeatedly merge the two smallest codegen units as long as:
-    // - we have more CGUs than the upper limit, or
-    // - (Non-incremental builds only) the user didn't specify a CGU count, and
-    //   there are multiple CGUs, and some are below the minimum size.
+    // Repeatedly merge the two smallest codegen units as long as: it's a
+    // non-incremental build, and the user didn't specify a CGU count, and
+    // there are multiple CGUs, and some are below the minimum size.
     //
     // The "didn't specify a CGU count" condition is because when an explicit
     // count is requested we observe it as closely as possible. For example,
     // the `compiler_builtins` crate sets `codegen-units = 10000` and it's
     // critical they aren't merged. Also, some tests use explicit small values
     // and likewise won't work if small CGUs are merged.
-    while codegen_units.len() > cx.tcx.sess.codegen_units().as_usize()
-        || (cx.tcx.sess.opts.incremental.is_none()
-            && matches!(cx.tcx.sess.codegen_units(), CodegenUnits::Default(_))
-            && codegen_units.len() > 1
-            && codegen_units.iter().any(|cgu| cgu.size_estimate() < NON_INCR_MIN_CGU_SIZE))
+    while cx.tcx.sess.opts.incremental.is_none()
+        && matches!(cx.tcx.sess.codegen_units(), CodegenUnits::Default(_))
+        && codegen_units.len() > 1
+        && codegen_units.iter().any(|cgu| cgu.size_estimate() < NON_INCR_MIN_CGU_SIZE)
     {
         // Sort small cgus to the back.
-        codegen_units.sort_by_key(|cgu| cmp::Reverse(cgu.size_estimate()));
+        codegen_units.sort_by_cached_key(|cgu| cmp::Reverse(cgu.size_estimate()));
 
         let mut smallest = codegen_units.pop().unwrap();
         let second_smallest = codegen_units.last_mut().unwrap();
@@ -351,16 +405,7 @@ fn merge_codegen_units<'tcx>(
         second_smallest.items_mut().extend(smallest.items_mut().drain());
         second_smallest.compute_size_estimate();
 
-        // Record that `second_smallest` now contains all the stuff that was
-        // in `smallest` before.
-        let mut consumed_cgu_names = cgu_contents.remove(&smallest.name()).unwrap();
-        cgu_contents.get_mut(&second_smallest.name()).unwrap().append(&mut consumed_cgu_names);
-
-        debug!(
-            "CodegenUnit {} merged into CodegenUnit {}",
-            smallest.name(),
-            second_smallest.name()
-        );
+        // Don't update `cgu_contents`, that's only for incremental builds.
     }
 
     let cgu_name_builder = &mut CodegenUnitNameBuilder::new(cx.tcx);
@@ -439,6 +484,25 @@ fn merge_codegen_units<'tcx>(
     }
 }
 
+/// Compute the combined size of all inlined items that appear in both `cgu1`
+/// and `cgu2`.
+fn compute_inlined_overlap<'tcx>(cgu1: &CodegenUnit<'tcx>, cgu2: &CodegenUnit<'tcx>) -> usize {
+    // Either order works. We pick the one that involves iterating over fewer
+    // items.
+    let (src_cgu, dst_cgu) =
+        if cgu1.items().len() <= cgu2.items().len() { (cgu1, cgu2) } else { (cgu2, cgu1) };
+
+    let mut overlap = 0;
+    for (item, data) in src_cgu.items().iter() {
+        if data.inlined {
+            if dst_cgu.items().contains_key(item) {
+                overlap += data.size_estimate;
+            }
+        }
+    }
+    overlap
+}
+
 fn internalize_symbols<'tcx>(
     cx: &PartitioningCx<'_, 'tcx>,
     codegen_units: &mut [CodegenUnit<'tcx>],
@@ -870,19 +934,16 @@ fn debug_dump<'a, 'tcx: 'a>(tcx: TyCtxt<'tcx>, label: &str, cgus: &[CodegenUnit<
             all_cgu_sizes.push(cgu.size_estimate());
 
             for (item, data) in cgu.items() {
-                match item.instantiation_mode(tcx) {
-                    InstantiationMode::GloballyShared { .. } => {
-                        root_items += 1;
-                        root_size += data.size_estimate;
-                    }
-                    InstantiationMode::LocalCopy => {
-                        if inlined_items.insert(item) {
-                            unique_inlined_items += 1;
-                            unique_inlined_size += data.size_estimate;
-                        }
-                        placed_inlined_items += 1;
-                        placed_inlined_size += data.size_estimate;
+                if !data.inlined {
+                    root_items += 1;
+                    root_size += data.size_estimate;
+                } else {
+                    if inlined_items.insert(item) {
+                        unique_inlined_items += 1;
+                        unique_inlined_size += data.size_estimate;
                     }
+                    placed_inlined_items += 1;
+                    placed_inlined_size += data.size_estimate;
                 }
             }
         }
@@ -937,10 +998,7 @@ fn debug_dump<'a, 'tcx: 'a>(tcx: TyCtxt<'tcx>, label: &str, cgus: &[CodegenUnit<
                 let symbol_name = item.symbol_name(tcx).name;
                 let symbol_hash_start = symbol_name.rfind('h');
                 let symbol_hash = symbol_hash_start.map_or("<no hash>", |i| &symbol_name[i..]);
-                let kind = match item.instantiation_mode(tcx) {
-                    InstantiationMode::GloballyShared { .. } => "root",
-                    InstantiationMode::LocalCopy => "inlined",
-                };
+                let kind = if !data.inlined { "root" } else { "inlined" };
                 let size = data.size_estimate;
                 let _ = with_no_trimmed_paths!(writeln!(
                     s,
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 8455803ad0c..c3cf6437afa 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -247,7 +247,7 @@ impl<'a> Parser<'a> {
         self.sess.span_diagnostic.struct_span_err(sp, m)
     }
 
-    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: impl Into<DiagnosticMessage>) -> ! {
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: impl Into<String>) -> ! {
         self.sess.span_diagnostic.span_bug(sp, m)
     }
 
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 7ede4fbc3d9..3ecdbc36248 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1309,7 +1309,7 @@ impl<'a> Parser<'a> {
 
     /// Assuming we have just parsed `.`, continue parsing into an expression.
     fn parse_dot_suffix(&mut self, self_arg: P<Expr>, lo: Span) -> PResult<'a, P<Expr>> {
-        if self.token.uninterpolated_span().rust_2018() && self.eat_keyword(kw::Await) {
+        if self.token.uninterpolated_span().at_least_rust_2018() && self.eat_keyword(kw::Await) {
             return Ok(self.mk_await_expr(self_arg, lo));
         }
 
@@ -1442,8 +1442,8 @@ impl<'a> Parser<'a> {
             self.parse_expr_let()
         } else if self.eat_keyword(kw::Underscore) {
             Ok(self.mk_expr(self.prev_token.span, ExprKind::Underscore))
-        } else if self.token.uninterpolated_span().rust_2018() {
-            // `Span::rust_2018()` is somewhat expensive; don't get it repeatedly.
+        } else if self.token.uninterpolated_span().at_least_rust_2018() {
+            // `Span:.at_least_rust_2018()` is somewhat expensive; don't get it repeatedly.
             if self.check_keyword(kw::Async) {
                 if self.is_async_block() {
                     // Check for `async {` and `async move {`.
@@ -2230,7 +2230,7 @@ impl<'a> Parser<'a> {
         let movability =
             if self.eat_keyword(kw::Static) { Movability::Static } else { Movability::Movable };
 
-        let asyncness = if self.token.uninterpolated_span().rust_2018() {
+        let asyncness = if self.token.uninterpolated_span().at_least_rust_2018() {
             self.parse_asyncness(Case::Sensitive)
         } else {
             Async::No
@@ -3014,7 +3014,7 @@ impl<'a> Parser<'a> {
     fn is_try_block(&self) -> bool {
         self.token.is_keyword(kw::Try)
             && self.look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Brace))
-            && self.token.uninterpolated_span().rust_2018()
+            && self.token.uninterpolated_span().at_least_rust_2018()
     }
 
     /// Parses an `async move? {...}` expression.
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index e4d843b7c8b..2e1a61e634e 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -1210,7 +1210,8 @@ impl<'a> Parser<'a> {
     fn parse_constness_(&mut self, case: Case, is_closure: bool) -> Const {
         // Avoid const blocks and const closures to be parsed as const items
         if (self.check_const_closure() == is_closure)
-            && self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
+            && !self
+                .look_ahead(1, |t| *t == token::OpenDelim(Delimiter::Brace) || t.is_whole_block())
             && self.eat_keyword_case(kw::Const, case)
         {
             Const::Yes(self.prev_token.uninterpolated_span())
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index fdf36517847..14891c45d81 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -8,7 +8,6 @@ use crate::errors::{
     TrailingVertNotAllowed, UnexpectedLifetimeInPattern, UnexpectedVertVertBeforeFunctionParam,
     UnexpectedVertVertInPattern,
 };
-use crate::fluent_generated as fluent;
 use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole};
 use rustc_ast::mut_visit::{noop_visit_pat, MutVisitor};
 use rustc_ast::ptr::P;
@@ -214,41 +213,25 @@ impl<'a> Parser<'a> {
 
         if let PatKind::Or(pats) = &pat.kind {
             let span = pat.span;
-
-            if trailing_vert {
-                // We already emitted an error and suggestion to remove the trailing vert. Don't
-                // emit again.
-
-                // FIXME(#100717): pass `TopLevelOrPatternNotAllowed::* { sub: None }` to
-                // `delay_span_bug()` instead of fluent message
-                self.sess.span_diagnostic.delay_span_bug(
-                    span,
-                    match syntax_loc {
-                        PatternLocation::LetBinding => {
-                            fluent::parse_or_pattern_not_allowed_in_let_binding
-                        }
-                        PatternLocation::FunctionParameter => {
-                            fluent::parse_or_pattern_not_allowed_in_fn_parameters
-                        }
-                    },
-                );
+            let pat = pprust::pat_to_string(&pat);
+            let sub = if pats.len() == 1 {
+                Some(TopLevelOrPatternNotAllowedSugg::RemoveLeadingVert { span, pat })
             } else {
-                let pat = pprust::pat_to_string(&pat);
-                let sub = if pats.len() == 1 {
-                    Some(TopLevelOrPatternNotAllowedSugg::RemoveLeadingVert { span, pat })
-                } else {
-                    Some(TopLevelOrPatternNotAllowedSugg::WrapInParens { span, pat })
-                };
+                Some(TopLevelOrPatternNotAllowedSugg::WrapInParens { span, pat })
+            };
 
-                self.sess.emit_err(match syntax_loc {
-                    PatternLocation::LetBinding => {
-                        TopLevelOrPatternNotAllowed::LetBinding { span, sub }
-                    }
-                    PatternLocation::FunctionParameter => {
-                        TopLevelOrPatternNotAllowed::FunctionParameter { span, sub }
-                    }
-                });
+            let mut err = self.sess.create_err(match syntax_loc {
+                PatternLocation::LetBinding => {
+                    TopLevelOrPatternNotAllowed::LetBinding { span, sub }
+                }
+                PatternLocation::FunctionParameter => {
+                    TopLevelOrPatternNotAllowed::FunctionParameter { span, sub }
+                }
+            });
+            if trailing_vert {
+                err.delay_as_bug();
             }
+            err.emit();
         }
 
         Ok((pat, colon))
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
index a29b696aea8..3bb50b05aa3 100644
--- a/compiler/rustc_parse/src/parser/ty.rs
+++ b/compiler/rustc_parse/src/parser/ty.rs
@@ -608,7 +608,7 @@ impl<'a> Parser<'a> {
     /// Is a `dyn B0 + ... + Bn` type allowed here?
     fn is_explicit_dyn_type(&mut self) -> bool {
         self.check_keyword(kw::Dyn)
-            && (self.token.uninterpolated_span().rust_2018()
+            && (self.token.uninterpolated_span().at_least_rust_2018()
                 || self.look_ahead(1, |t| {
                     (t.can_begin_bound() || t.kind == TokenKind::BinOp(token::Star))
                         && !can_continue_type_after_non_fn_ident(t)
diff --git a/compiler/rustc_parse_format/src/lib.rs b/compiler/rustc_parse_format/src/lib.rs
index 7de84db211e..88452ccdf05 100644
--- a/compiler/rustc_parse_format/src/lib.rs
+++ b/compiler/rustc_parse_format/src/lib.rs
@@ -109,6 +109,8 @@ pub struct Argument<'a> {
 pub struct FormatSpec<'a> {
     /// Optionally specified character to fill alignment with.
     pub fill: Option<char>,
+    /// Span of the optionally specified fill character.
+    pub fill_span: Option<InnerSpan>,
     /// Optionally specified alignment.
     pub align: Alignment,
     /// The `+` or `-` flag.
@@ -264,7 +266,7 @@ impl<'a> Iterator for Parser<'a> {
                         Some(String(self.string(pos + 1)))
                     } else {
                         let arg = self.argument(lbrace_end);
-                        if let Some(rbrace_pos) = self.must_consume('}') {
+                        if let Some(rbrace_pos) = self.consume_closing_brace(&arg) {
                             if self.is_source_literal {
                                 let lbrace_byte_pos = self.to_span_index(pos);
                                 let rbrace_byte_pos = self.to_span_index(rbrace_pos);
@@ -450,69 +452,51 @@ impl<'a> Parser<'a> {
 
     /// Forces consumption of the specified character. If the character is not
     /// found, an error is emitted.
-    fn must_consume(&mut self, c: char) -> Option<usize> {
+    fn consume_closing_brace(&mut self, arg: &Argument<'_>) -> Option<usize> {
         self.ws();
 
-        if let Some(&(pos, maybe)) = self.cur.peek() {
-            if c == maybe {
+        let pos;
+        let description;
+
+        if let Some(&(peek_pos, maybe)) = self.cur.peek() {
+            if maybe == '}' {
                 self.cur.next();
-                Some(pos)
-            } else {
-                let pos = self.to_span_index(pos);
-                let description = format!("expected `'}}'`, found `{maybe:?}`");
-                let label = "expected `}`".to_owned();
-                let (note, secondary_label) = if c == '}' {
-                    (
-                        Some(
-                            "if you intended to print `{`, you can escape it using `{{`".to_owned(),
-                        ),
-                        self.last_opening_brace
-                            .map(|sp| ("because of this opening brace".to_owned(), sp)),
-                    )
-                } else {
-                    (None, None)
-                };
-                self.errors.push(ParseError {
-                    description,
-                    note,
-                    label,
-                    span: pos.to(pos),
-                    secondary_label,
-                    should_be_replaced_with_positional_argument: false,
-                });
-                None
+                return Some(peek_pos);
             }
+
+            pos = peek_pos;
+            description = format!("expected `'}}'`, found `{maybe:?}`");
         } else {
-            let description = format!("expected `{c:?}` but string was terminated");
+            description = "expected `'}'` but string was terminated".to_owned();
             // point at closing `"`
-            let pos = self.input.len() - if self.append_newline { 1 } else { 0 };
-            let pos = self.to_span_index(pos);
-            if c == '}' {
-                let label = format!("expected `{c:?}`");
-                let (note, secondary_label) = if c == '}' {
-                    (
-                        Some(
-                            "if you intended to print `{`, you can escape it using `{{`".to_owned(),
-                        ),
-                        self.last_opening_brace
-                            .map(|sp| ("because of this opening brace".to_owned(), sp)),
-                    )
-                } else {
-                    (None, None)
-                };
-                self.errors.push(ParseError {
-                    description,
-                    note,
-                    label,
-                    span: pos.to(pos),
-                    secondary_label,
-                    should_be_replaced_with_positional_argument: false,
-                });
-            } else {
-                self.err(description, format!("expected `{c:?}`"), pos.to(pos));
-            }
-            None
+            pos = self.input.len() - if self.append_newline { 1 } else { 0 };
         }
+
+        let pos = self.to_span_index(pos);
+
+        let label = "expected `'}'`".to_owned();
+        let (note, secondary_label) = if arg.format.fill == Some('}') {
+            (
+                Some("the character `'}'` is interpreted as a fill character because of the `:` that precedes it".to_owned()),
+                arg.format.fill_span.map(|sp| ("this is not interpreted as a formatting closing brace".to_owned(), sp)),
+            )
+        } else {
+            (
+                Some("if you intended to print `{`, you can escape it using `{{`".to_owned()),
+                self.last_opening_brace.map(|sp| ("because of this opening brace".to_owned(), sp)),
+            )
+        };
+
+        self.errors.push(ParseError {
+            description,
+            note,
+            label,
+            span: pos.to(pos),
+            secondary_label,
+            should_be_replaced_with_positional_argument: false,
+        });
+
+        None
     }
 
     /// Consumes all whitespace characters until the first non-whitespace character
@@ -608,6 +592,7 @@ impl<'a> Parser<'a> {
     fn format(&mut self) -> FormatSpec<'a> {
         let mut spec = FormatSpec {
             fill: None,
+            fill_span: None,
             align: AlignUnknown,
             sign: None,
             alternate: false,
@@ -625,9 +610,10 @@ impl<'a> Parser<'a> {
         }
 
         // fill character
-        if let Some(&(_, c)) = self.cur.peek() {
+        if let Some(&(idx, c)) = self.cur.peek() {
             if let Some((_, '>' | '<' | '^')) = self.cur.clone().nth(1) {
                 spec.fill = Some(c);
+                spec.fill_span = Some(self.span(idx, idx + 1));
                 self.cur.next();
             }
         }
@@ -722,6 +708,7 @@ impl<'a> Parser<'a> {
     fn inline_asm(&mut self) -> FormatSpec<'a> {
         let mut spec = FormatSpec {
             fill: None,
+            fill_span: None,
             align: AlignUnknown,
             sign: None,
             alternate: false,
diff --git a/compiler/rustc_parse_format/src/tests.rs b/compiler/rustc_parse_format/src/tests.rs
index 45314e2fb55..0c594f9104c 100644
--- a/compiler/rustc_parse_format/src/tests.rs
+++ b/compiler/rustc_parse_format/src/tests.rs
@@ -9,6 +9,7 @@ fn same(fmt: &'static str, p: &[Piece<'static>]) {
 fn fmtdflt() -> FormatSpec<'static> {
     return FormatSpec {
         fill: None,
+        fill_span: None,
         align: AlignUnknown,
         sign: None,
         alternate: false,
@@ -128,6 +129,7 @@ fn format_type() {
             position_span: InnerSpan { start: 2, end: 3 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -152,6 +154,7 @@ fn format_align_fill() {
             position_span: InnerSpan { start: 2, end: 3 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignRight,
                 sign: None,
                 alternate: false,
@@ -173,6 +176,7 @@ fn format_align_fill() {
             position_span: InnerSpan { start: 2, end: 3 },
             format: FormatSpec {
                 fill: Some('0'),
+                fill_span: Some(InnerSpan::new(4, 5)),
                 align: AlignLeft,
                 sign: None,
                 alternate: false,
@@ -194,6 +198,7 @@ fn format_align_fill() {
             position_span: InnerSpan { start: 2, end: 3 },
             format: FormatSpec {
                 fill: Some('*'),
+                fill_span: Some(InnerSpan::new(4, 5)),
                 align: AlignLeft,
                 sign: None,
                 alternate: false,
@@ -218,6 +223,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -239,6 +245,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -260,6 +267,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 3 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -281,6 +289,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -302,6 +311,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -323,6 +333,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -344,6 +355,7 @@ fn format_counts() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: None,
                 alternate: false,
@@ -368,6 +380,7 @@ fn format_flags() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: Some(Sign::Minus),
                 alternate: false,
@@ -389,6 +402,7 @@ fn format_flags() {
             position_span: InnerSpan { start: 2, end: 2 },
             format: FormatSpec {
                 fill: None,
+                fill_span: None,
                 align: AlignUnknown,
                 sign: Some(Sign::Plus),
                 alternate: true,
@@ -415,6 +429,7 @@ fn format_mixture() {
                 position_span: InnerSpan { start: 7, end: 8 },
                 format: FormatSpec {
                     fill: None,
+                    fill_span: None,
                     align: AlignUnknown,
                     sign: None,
                     alternate: false,
diff --git a/compiler/rustc_query_system/messages.ftl b/compiler/rustc_query_system/messages.ftl
index 49b423d1ade..d5fed8fe179 100644
--- a/compiler/rustc_query_system/messages.ftl
+++ b/compiler/rustc_query_system/messages.ftl
@@ -1,4 +1,5 @@
 query_system_cycle = cycle detected when {$stack_bottom}
+    .note = see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 query_system_cycle_recursive_trait_alias = trait aliases cannot be recursive
 
diff --git a/compiler/rustc_query_system/src/error.rs b/compiler/rustc_query_system/src/error.rs
index cf2f04c7486..e49e78cc7c4 100644
--- a/compiler/rustc_query_system/src/error.rs
+++ b/compiler/rustc_query_system/src/error.rs
@@ -57,6 +57,8 @@ pub struct Cycle {
     pub alias: Option<Alias>,
     #[subdiagnostic]
     pub cycle_usage: Option<CycleUsage>,
+    #[note]
+    pub note_span: (),
 }
 
 #[derive(Diagnostic)]
diff --git a/compiler/rustc_query_system/src/query/job.rs b/compiler/rustc_query_system/src/query/job.rs
index f45f7ca5da6..d2140161f1d 100644
--- a/compiler/rustc_query_system/src/query/job.rs
+++ b/compiler/rustc_query_system/src/query/job.rs
@@ -13,6 +13,7 @@ use rustc_session::Session;
 use rustc_span::Span;
 
 use std::hash::Hash;
+use std::io::Write;
 use std::num::NonZeroU64;
 
 #[cfg(parallel_compiler)]
@@ -607,6 +608,7 @@ pub(crate) fn report_cycle<'a, D: DepKind>(
         alias,
         cycle_usage: cycle_usage,
         stack_count,
+        note_span: (),
     };
 
     cycle_diag.into_diagnostic(&sess.parse_sess.span_diagnostic)
@@ -617,30 +619,50 @@ pub fn print_query_stack<Qcx: QueryContext>(
     mut current_query: Option<QueryJobId>,
     handler: &Handler,
     num_frames: Option<usize>,
+    mut file: Option<std::fs::File>,
 ) -> usize {
     // Be careful relying on global state here: this code is called from
     // a panic hook, which means that the global `Handler` may be in a weird
     // state if it was responsible for triggering the panic.
-    let mut i = 0;
+    let mut count_printed = 0;
+    let mut count_total = 0;
     let query_map = qcx.try_collect_active_jobs();
 
+    if let Some(ref mut file) = file {
+        let _ = writeln!(file, "\n\nquery stack during panic:");
+    }
     while let Some(query) = current_query {
-        if Some(i) == num_frames {
-            break;
-        }
         let Some(query_info) = query_map.as_ref().and_then(|map| map.get(&query)) else {
             break;
         };
-        let mut diag = Diagnostic::new(
-            Level::FailureNote,
-            format!("#{} [{:?}] {}", i, query_info.query.dep_kind, query_info.query.description),
-        );
-        diag.span = query_info.job.span.into();
-        handler.force_print_diagnostic(diag);
+        if Some(count_printed) < num_frames || num_frames.is_none() {
+            // Only print to stderr as many stack frames as `num_frames` when present.
+            let mut diag = Diagnostic::new(
+                Level::FailureNote,
+                format!(
+                    "#{} [{:?}] {}",
+                    count_printed, query_info.query.dep_kind, query_info.query.description
+                ),
+            );
+            diag.span = query_info.job.span.into();
+            handler.force_print_diagnostic(diag);
+            count_printed += 1;
+        }
+
+        if let Some(ref mut file) = file {
+            let _ = writeln!(
+                file,
+                "#{} [{:?}] {}",
+                count_total, query_info.query.dep_kind, query_info.query.description
+            );
+        }
 
         current_query = query_info.job.parent;
-        i += 1;
+        count_total += 1;
     }
 
-    i
+    if let Some(ref mut file) = file {
+        let _ = writeln!(file, "end of query stack");
+    }
+    count_printed
 }
diff --git a/compiler/rustc_resolve/src/check_unused.rs b/compiler/rustc_resolve/src/check_unused.rs
index dc35c8b176f..3228e8d52f0 100644
--- a/compiler/rustc_resolve/src/check_unused.rs
+++ b/compiler/rustc_resolve/src/check_unused.rs
@@ -440,7 +440,7 @@ impl Resolver<'_, '_> {
 
             // If we are not in Rust 2018 edition, then we don't make any further
             // suggestions.
-            if !tcx.sess.rust_2018() {
+            if !tcx.sess.at_least_rust_2018() {
                 continue;
             }
 
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index d3dcdfa4275..2cfde2f62d8 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1203,7 +1203,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     if filter_fn(res) {
                         // create the path
                         let mut segms = path_segments.clone();
-                        if lookup_ident.span.rust_2018() {
+                        if lookup_ident.span.at_least_rust_2018() {
                             // crate-local absolute paths start with `crate::` in edition 2018
                             // FIXME: may also be stabilized for Rust 2015 (Issues #45477, #44660)
                             segms.insert(0, ast::PathSegment::from_ident(crate_name));
@@ -1268,7 +1268,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     path_segments.push(ast::PathSegment::from_ident(ident));
 
                     let is_extern_crate_that_also_appears_in_prelude =
-                        name_binding.is_extern_crate() && lookup_ident.span.rust_2018();
+                        name_binding.is_extern_crate() && lookup_ident.span.at_least_rust_2018();
 
                     if !is_extern_crate_that_also_appears_in_prelude {
                         // add the module to the lookup
@@ -1315,7 +1315,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             &filter_fn,
         );
 
-        if lookup_ident.span.rust_2018() {
+        if lookup_ident.span.at_least_rust_2018() {
             let extern_prelude_names = self.extern_prelude.clone();
             for (ident, _) in extern_prelude_names.into_iter() {
                 if ident.span.from_expansion() {
@@ -1568,7 +1568,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                     "consider adding an explicit import of `{ident}` to disambiguate"
                 ))
             }
-            if b.is_extern_crate() && ident.span.rust_2018() {
+            if b.is_extern_crate() && ident.span.at_least_rust_2018() {
                 help_msgs.push(format!("use `::{ident}` to refer to this {thing} unambiguously"))
             }
             match misc {
@@ -1973,7 +1973,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 if fst.ident.name == kw::PathRoot && !snd.ident.is_path_segment_keyword() => {}
             // `ident::...` on 2018.
             (Some(fst), _)
-                if fst.ident.span.rust_2018() && !fst.ident.is_path_segment_keyword() =>
+                if fst.ident.span.at_least_rust_2018() && !fst.ident.is_path_segment_keyword() =>
             {
                 // Insert a placeholder that's later replaced by `self`/`super`/etc.
                 path.insert(0, Segment::from_ident(Ident::empty()));
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index 520fab1f0c8..de431444769 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -1417,13 +1417,13 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         ));
                         continue;
                     }
-                    if name == kw::PathRoot && ident.span.rust_2018() {
+                    if name == kw::PathRoot && ident.span.at_least_rust_2018() {
                         module = Some(ModuleOrUniformRoot::ExternPrelude);
                         continue;
                     }
                     if name == kw::PathRoot
                         && ident.span.is_rust_2015()
-                        && self.tcx.sess.rust_2018()
+                        && self.tcx.sess.at_least_rust_2018()
                     {
                         // `::a::b` from 2015 macro on 2018 global edition
                         module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude);
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 846a1ffe09b..05128a51016 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -3911,8 +3911,9 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             && path[0].ident.name != kw::PathRoot
             && path[0].ident.name != kw::DollarCrate
         {
+            let last_segment = *path.last().unwrap();
             let unqualified_result = {
-                match self.resolve_path(&[*path.last().unwrap()], Some(ns), None) {
+                match self.resolve_path(&[last_segment], Some(ns), None) {
                     PathResult::NonModule(path_res) => path_res.expect_full_res(),
                     PathResult::Module(ModuleOrUniformRoot::Module(module)) => {
                         module.res().unwrap()
@@ -3928,8 +3929,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                     finalize.path_span,
                     "unnecessary qualification",
                     lint::BuiltinLintDiagnostics::UnusedQualifications {
-                        path_span: finalize.path_span,
-                        unqualified_path: path.last().unwrap().ident
+                        removal_span: finalize.path_span.until(last_segment.ident.span),
                     }
                 )
             }
diff --git a/compiler/rustc_session/src/cstore.rs b/compiler/rustc_session/src/cstore.rs
index dc475e8c6d5..c53a355b533 100644
--- a/compiler/rustc_session/src/cstore.rs
+++ b/compiler/rustc_session/src/cstore.rs
@@ -13,6 +13,7 @@ use rustc_hir::definitions::{DefKey, DefPath, DefPathHash, Definitions};
 use rustc_span::hygiene::{ExpnHash, ExpnId};
 use rustc_span::symbol::Symbol;
 use rustc_span::Span;
+use rustc_target::spec::abi::Abi;
 use rustc_target::spec::Target;
 
 use std::any::Any;
@@ -147,6 +148,7 @@ pub enum DllCallingConvention {
 pub struct ForeignModule {
     pub foreign_items: Vec<DefId>,
     pub def_id: DefId,
+    pub abi: Abi,
 }
 
 #[derive(Copy, Clone, Debug, HashStable_Generic)]
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 194f7201ff3..b0a67c564ce 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -117,6 +117,7 @@ pub fn feature_err_issue(
 /// Construct a future incompatibility diagnostic for a feature gate.
 ///
 /// This diagnostic is only a warning and *does not cause compilation to fail*.
+#[track_caller]
 pub fn feature_warn(sess: &ParseSess, feature: Symbol, span: Span, explain: &'static str) {
     feature_warn_issue(sess, feature, span, GateIssue::Language, explain);
 }
@@ -129,6 +130,7 @@ pub fn feature_warn(sess: &ParseSess, feature: Symbol, span: Span, explain: &'st
 /// Almost always, you want to use this for a language feature. If so, prefer `feature_warn`.
 #[allow(rustc::diagnostic_outside_of_impl)]
 #[allow(rustc::untranslatable_diagnostic)]
+#[track_caller]
 pub fn feature_warn_issue(
     sess: &ParseSess,
     feature: Symbol,
@@ -229,6 +231,7 @@ impl ParseSess {
             Some(sm.clone()),
             None,
             fallback_bundle,
+            None,
         );
         ParseSess::with_span_handler(handler, sm)
     }
@@ -259,12 +262,20 @@ impl ParseSess {
     pub fn with_silent_emitter(fatal_note: Option<String>) -> Self {
         let fallback_bundle = fallback_fluent_bundle(Vec::new(), false);
         let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
-        let fatal_handler =
-            Handler::with_tty_emitter(ColorConfig::Auto, false, None, None, None, fallback_bundle);
+        let fatal_handler = Handler::with_tty_emitter(
+            ColorConfig::Auto,
+            false,
+            None,
+            None,
+            None,
+            fallback_bundle,
+            None,
+        );
         let handler = Handler::with_emitter(
             false,
             None,
             Box::new(SilentEmitter { fatal_handler, fatal_note }),
+            None,
         );
         ParseSess::with_span_handler(handler, sm)
     }
@@ -351,6 +362,7 @@ impl ParseSess {
         self.create_warning(warning).emit()
     }
 
+    #[track_caller]
     pub fn create_note<'a>(
         &'a self,
         note: impl IntoDiagnostic<'a, Noted>,
@@ -358,10 +370,12 @@ impl ParseSess {
         note.into_diagnostic(&self.span_diagnostic)
     }
 
+    #[track_caller]
     pub fn emit_note<'a>(&'a self, note: impl IntoDiagnostic<'a, Noted>) -> Noted {
         self.create_note(note).emit()
     }
 
+    #[track_caller]
     pub fn create_fatal<'a>(
         &'a self,
         fatal: impl IntoDiagnostic<'a, !>,
@@ -369,6 +383,7 @@ impl ParseSess {
         fatal.into_diagnostic(&self.span_diagnostic)
     }
 
+    #[track_caller]
     pub fn emit_fatal<'a>(&'a self, fatal: impl IntoDiagnostic<'a, !>) -> ! {
         self.create_fatal(fatal).emit()
     }
@@ -383,16 +398,19 @@ impl ParseSess {
     }
 
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
         self.span_diagnostic.struct_warn(msg)
     }
 
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_fatal(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, !> {
         self.span_diagnostic.struct_fatal(msg)
     }
 
     #[rustc_lint_diagnostics]
+    #[track_caller]
     pub fn struct_diagnostic<G: EmissionGuarantee>(
         &self,
         msg: impl Into<DiagnosticMessage>,
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 5be122ffbde..146bb11bd3a 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -677,7 +677,7 @@ impl Session {
     pub fn delay_span_bug<S: Into<MultiSpan>>(
         &self,
         sp: S,
-        msg: impl Into<DiagnosticMessage>,
+        msg: impl Into<String>,
     ) -> ErrorGuaranteed {
         self.diagnostic().delay_span_bug(sp, msg)
     }
@@ -995,18 +995,18 @@ impl Session {
     }
 
     /// Are we allowed to use features from the Rust 2018 edition?
-    pub fn rust_2018(&self) -> bool {
-        self.edition().rust_2018()
+    pub fn at_least_rust_2018(&self) -> bool {
+        self.edition().at_least_rust_2018()
     }
 
     /// Are we allowed to use features from the Rust 2021 edition?
-    pub fn rust_2021(&self) -> bool {
-        self.edition().rust_2021()
+    pub fn at_least_rust_2021(&self) -> bool {
+        self.edition().at_least_rust_2021()
     }
 
     /// Are we allowed to use features from the Rust 2024 edition?
-    pub fn rust_2024(&self) -> bool {
-        self.edition().rust_2024()
+    pub fn at_least_rust_2024(&self) -> bool {
+        self.edition().at_least_rust_2024()
     }
 
     /// Returns `true` if we should use the PLT for shared library calls.
@@ -1392,6 +1392,7 @@ pub fn build_session(
     file_loader: Option<Box<dyn FileLoader + Send + Sync + 'static>>,
     target_override: Option<Target>,
     cfg_version: &'static str,
+    ice_file: Option<PathBuf>,
 ) -> Session {
     // FIXME: This is not general enough to make the warning lint completely override
     // normal diagnostic warnings, since the warning lint can also be denied and changed
@@ -1440,6 +1441,7 @@ pub fn build_session(
     let span_diagnostic = rustc_errors::Handler::with_emitter_and_flags(
         emitter,
         sopts.unstable_opts.diagnostic_handler_flags(can_emit_warnings),
+        ice_file,
     );
 
     let self_profiler = if let SwitchWithOptPath::Enabled(ref d) = sopts.unstable_opts.self_profile
@@ -1731,7 +1733,7 @@ pub struct EarlyErrorHandler {
 impl EarlyErrorHandler {
     pub fn new(output: ErrorOutputType) -> Self {
         let emitter = mk_emitter(output);
-        Self { handler: rustc_errors::Handler::with_emitter(true, None, emitter) }
+        Self { handler: rustc_errors::Handler::with_emitter(true, None, emitter, None) }
     }
 
     pub fn abort_if_errors(&self) {
@@ -1745,7 +1747,7 @@ impl EarlyErrorHandler {
         self.handler.abort_if_errors();
 
         let emitter = mk_emitter(output);
-        self.handler = Handler::with_emitter(true, None, emitter);
+        self.handler = Handler::with_emitter(true, None, emitter, None);
     }
 
     #[allow(rustc::untranslatable_diagnostic)]
diff --git a/compiler/rustc_smir/src/rustc_smir/mod.rs b/compiler/rustc_smir/src/rustc_smir/mod.rs
index 6af6cfe58f1..0e5de1e74d3 100644
--- a/compiler/rustc_smir/src/rustc_smir/mod.rs
+++ b/compiler/rustc_smir/src/rustc_smir/mod.rs
@@ -119,8 +119,12 @@ impl<'tcx> Tables<'tcx> {
                 TyKind::RigidTy(RigidTy::Array(self.intern_ty(*ty), opaque(constant)))
             }
             ty::Slice(ty) => TyKind::RigidTy(RigidTy::Slice(self.intern_ty(*ty))),
-            ty::RawPtr(_) => todo!(),
-            ty::Ref(_, _, _) => todo!(),
+            ty::RawPtr(ty::TypeAndMut { ty, mutbl }) => {
+                TyKind::RigidTy(RigidTy::RawPtr(self.intern_ty(*ty), mutbl.stable()))
+            }
+            ty::Ref(region, ty, mutbl) => {
+                TyKind::RigidTy(RigidTy::Ref(opaque(region), self.intern_ty(*ty), mutbl.stable()))
+            }
             ty::FnDef(_, _) => todo!(),
             ty::FnPtr(_) => todo!(),
             ty::Dynamic(_, _, _) => todo!(),
diff --git a/compiler/rustc_smir/src/stable_mir/mir/body.rs b/compiler/rustc_smir/src/stable_mir/mir/body.rs
index 02ac907f09a..831eb6589e4 100644
--- a/compiler/rustc_smir/src/stable_mir/mir/body.rs
+++ b/compiler/rustc_smir/src/stable_mir/mir/body.rs
@@ -1,4 +1,4 @@
-use crate::rustc_internal::Opaque;
+use crate::stable_mir::ty::Region;
 use crate::stable_mir::{self, ty::Ty};
 
 #[derive(Clone, Debug)]
@@ -137,8 +137,6 @@ pub enum Statement {
     Nop,
 }
 
-type Region = Opaque;
-
 // FIXME this is incomplete
 #[derive(Clone, Debug)]
 pub enum Rvalue {
diff --git a/compiler/rustc_smir/src/stable_mir/ty.rs b/compiler/rustc_smir/src/stable_mir/ty.rs
index e9f17f92c04..7ae07efb729 100644
--- a/compiler/rustc_smir/src/stable_mir/ty.rs
+++ b/compiler/rustc_smir/src/stable_mir/ty.rs
@@ -1,4 +1,4 @@
-use super::{with, DefId};
+use super::{mir::Mutability, with, DefId};
 use crate::rustc_internal::Opaque;
 
 #[derive(Copy, Clone, Debug)]
@@ -11,7 +11,7 @@ impl Ty {
 }
 
 type Const = Opaque;
-type Region = Opaque;
+pub(crate) type Region = Opaque;
 
 #[derive(Clone, Debug)]
 pub enum TyKind {
@@ -29,6 +29,8 @@ pub enum RigidTy {
     Str,
     Array(Ty, Const),
     Slice(Ty),
+    RawPtr(Ty, Mutability),
+    Ref(Region, Ty, Mutability),
     Tuple(Vec<Ty>),
 }
 
diff --git a/compiler/rustc_span/src/edition.rs b/compiler/rustc_span/src/edition.rs
index f16db69aae2..608b8c24bde 100644
--- a/compiler/rustc_span/src/edition.rs
+++ b/compiler/rustc_span/src/edition.rs
@@ -82,17 +82,17 @@ impl Edition {
     }
 
     /// Are we allowed to use features from the Rust 2018 edition?
-    pub fn rust_2018(self) -> bool {
+    pub fn at_least_rust_2018(self) -> bool {
         self >= Edition::Edition2018
     }
 
     /// Are we allowed to use features from the Rust 2021 edition?
-    pub fn rust_2021(self) -> bool {
+    pub fn at_least_rust_2021(self) -> bool {
         self >= Edition::Edition2021
     }
 
     /// Are we allowed to use features from the Rust 2024 edition?
-    pub fn rust_2024(self) -> bool {
+    pub fn at_least_rust_2024(self) -> bool {
         self >= Edition::Edition2024
     }
 }
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 5c56337d1e0..ecaa82874a3 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -707,24 +707,28 @@ impl Span {
         self.ctxt().edition()
     }
 
+    /// Is this edition 2015?
     #[inline]
     pub fn is_rust_2015(self) -> bool {
         self.edition().is_rust_2015()
     }
 
+    /// Are we allowed to use features from the Rust 2018 edition?
     #[inline]
-    pub fn rust_2018(self) -> bool {
-        self.edition().rust_2018()
+    pub fn at_least_rust_2018(self) -> bool {
+        self.edition().at_least_rust_2018()
     }
 
+    /// Are we allowed to use features from the Rust 2021 edition?
     #[inline]
-    pub fn rust_2021(self) -> bool {
-        self.edition().rust_2021()
+    pub fn at_least_rust_2021(self) -> bool {
+        self.edition().at_least_rust_2021()
     }
 
+    /// Are we allowed to use features from the Rust 2024 edition?
     #[inline]
-    pub fn rust_2024(self) -> bool {
-        self.edition().rust_2024()
+    pub fn at_least_rust_2024(self) -> bool {
+        self.edition().at_least_rust_2024()
     }
 
     /// Returns the source callee.
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index 03e7b3e7b40..3d2ea017d8f 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -693,8 +693,8 @@ impl<'a, Ty> FnAbi<'a, Ty> {
             "avr" => avr::compute_abi_info(self),
             "loongarch64" => loongarch::compute_abi_info(cx, self),
             "m68k" => m68k::compute_abi_info(self),
-            "mips" => mips::compute_abi_info(cx, self),
-            "mips64" => mips64::compute_abi_info(cx, self),
+            "mips" | "mips32r6" => mips::compute_abi_info(cx, self),
+            "mips64" | "mips64r6" => mips64::compute_abi_info(cx, self),
             "powerpc" => powerpc::compute_abi_info(self),
             "powerpc64" => powerpc64::compute_abi_info(cx, self),
             "s390x" => s390x::compute_abi_info(cx, self),
diff --git a/compiler/rustc_target/src/asm/mod.rs b/compiler/rustc_target/src/asm/mod.rs
index e60b8e78e5d..7c27732079b 100644
--- a/compiler/rustc_target/src/asm/mod.rs
+++ b/compiler/rustc_target/src/asm/mod.rs
@@ -238,8 +238,8 @@ impl FromStr for InlineAsmArch {
             "powerpc64" => Ok(Self::PowerPC64),
             "hexagon" => Ok(Self::Hexagon),
             "loongarch64" => Ok(Self::LoongArch64),
-            "mips" => Ok(Self::Mips),
-            "mips64" => Ok(Self::Mips64),
+            "mips" | "mips32r6" => Ok(Self::Mips),
+            "mips64" | "mips64r6" => Ok(Self::Mips64),
             "s390x" => Ok(Self::S390x),
             "spirv" => Ok(Self::SpirV),
             "wasm32" => Ok(Self::Wasm32),
diff --git a/compiler/rustc_target/src/spec/mipsisa32r6_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/mipsisa32r6_unknown_linux_gnu.rs
index 1e066b271e2..983a449b006 100644
--- a/compiler/rustc_target/src/spec/mipsisa32r6_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/mipsisa32r6_unknown_linux_gnu.rs
@@ -6,7 +6,7 @@ pub fn target() -> Target {
         llvm_target: "mipsisa32r6-unknown-linux-gnu".into(),
         pointer_width: 32,
         data_layout: "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64".into(),
-        arch: "mips".into(),
+        arch: "mips32r6".into(),
         options: TargetOptions {
             endian: Endian::Big,
             cpu: "mips32r6".into(),
diff --git a/compiler/rustc_target/src/spec/mipsisa32r6el_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/mipsisa32r6el_unknown_linux_gnu.rs
index 4785929c100..ec0facdfb7b 100644
--- a/compiler/rustc_target/src/spec/mipsisa32r6el_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/mipsisa32r6el_unknown_linux_gnu.rs
@@ -5,7 +5,7 @@ pub fn target() -> Target {
         llvm_target: "mipsisa32r6el-unknown-linux-gnu".into(),
         pointer_width: 32,
         data_layout: "e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64".into(),
-        arch: "mips".into(),
+        arch: "mips32r6".into(),
 
         options: TargetOptions {
             cpu: "mips32r6".into(),
diff --git a/compiler/rustc_target/src/spec/mipsisa64r6_unknown_linux_gnuabi64.rs b/compiler/rustc_target/src/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
index 766ac768064..16dd1c416f4 100644
--- a/compiler/rustc_target/src/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
+++ b/compiler/rustc_target/src/spec/mipsisa64r6_unknown_linux_gnuabi64.rs
@@ -6,7 +6,7 @@ pub fn target() -> Target {
         llvm_target: "mipsisa64r6-unknown-linux-gnuabi64".into(),
         pointer_width: 64,
         data_layout: "E-m:e-i8:8:32-i16:16:32-i64:64-n32:64-S128".into(),
-        arch: "mips64".into(),
+        arch: "mips64r6".into(),
         options: TargetOptions {
             abi: "abi64".into(),
             endian: Endian::Big,
diff --git a/compiler/rustc_target/src/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs b/compiler/rustc_target/src/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
index d2b07c654dc..8d0a6aa8f51 100644
--- a/compiler/rustc_target/src/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
+++ b/compiler/rustc_target/src/spec/mipsisa64r6el_unknown_linux_gnuabi64.rs
@@ -5,7 +5,7 @@ pub fn target() -> Target {
         llvm_target: "mipsisa64r6el-unknown-linux-gnuabi64".into(),
         pointer_width: 64,
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-n32:64-S128".into(),
-        arch: "mips64".into(),
+        arch: "mips64r6".into(),
         options: TargetOptions {
             abi: "abi64".into(),
             // NOTE(mips64r6) matches C toolchain
diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index 312bd38178f..6efc1e7302c 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -1,5 +1,5 @@
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
-use crate::traits::{self, ObligationCtxt};
+use crate::traits::{self, DefiningAnchor, ObligationCtxt};
 
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
@@ -80,7 +80,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
 
 pub trait InferCtxtBuilderExt<'tcx> {
     fn enter_canonical_trait_query<K, R>(
-        &mut self,
+        self,
         canonical_key: &Canonical<'tcx, K>,
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
     ) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
@@ -108,7 +108,7 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
     /// have `'tcx` be free on this function so that we can talk about
     /// `K: TypeFoldable<TyCtxt<'tcx>>`.)
     fn enter_canonical_trait_query<K, R>(
-        &mut self,
+        self,
         canonical_key: &Canonical<'tcx, K>,
         operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
     ) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
@@ -117,8 +117,9 @@ impl<'tcx> InferCtxtBuilderExt<'tcx> for InferCtxtBuilder<'tcx> {
         R: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
     {
-        let (infcx, key, canonical_inference_vars) =
-            self.build_with_canonical(DUMMY_SP, canonical_key);
+        let (infcx, key, canonical_inference_vars) = self
+            .with_opaque_type_inference(DefiningAnchor::Bubble)
+            .build_with_canonical(DUMMY_SP, canonical_key);
         let ocx = ObligationCtxt::new(&infcx);
         let value = operation(&ocx, key)?;
         ocx.make_canonicalized_query_response(canonical_inference_vars, value)
diff --git a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
index 3a1302e46ba..a8ba98bef6d 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs
@@ -148,7 +148,7 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>(
 
         ty::Adt(def, args) => {
             let sized_crit = def.sized_constraint(ecx.tcx());
-            Ok(sized_crit.arg_iter_copied(ecx.tcx(), args).collect())
+            Ok(sized_crit.iter_instantiated_copied(ecx.tcx(), args).collect())
         }
     }
 }
@@ -353,7 +353,8 @@ pub(in crate::solve) fn predicates_for_object_candidate<'tcx>(
         // FIXME(associated_const_equality): Also add associated consts to
         // the requirements here.
         if item.kind == ty::AssocKind::Type {
-            requirements.extend(tcx.item_bounds(item.def_id).arg_iter(tcx, trait_ref.args));
+            requirements
+                .extend(tcx.item_bounds(item.def_id).iter_instantiated(tcx, trait_ref.args));
         }
     }
 
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 56d5d698d90..e086489b1bc 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2133,7 +2133,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                 Where(
                     obligation
                         .predicate
-                        .rebind(sized_crit.arg_iter_copied(self.tcx(), args).collect()),
+                        .rebind(sized_crit.iter_instantiated_copied(self.tcx(), args).collect()),
                 )
             }
 
diff --git a/compiler/rustc_transmute/src/lib.rs b/compiler/rustc_transmute/src/lib.rs
index 34ad6bd8c69..05ad4a4a12a 100644
--- a/compiler/rustc_transmute/src/lib.rs
+++ b/compiler/rustc_transmute/src/lib.rs
@@ -78,6 +78,7 @@ mod rustc {
     use rustc_middle::ty::ParamEnv;
     use rustc_middle::ty::Ty;
     use rustc_middle::ty::TyCtxt;
+    use rustc_middle::ty::ValTree;
 
     /// The source and destination types of a transmutation.
     #[derive(TypeVisitable, Debug, Clone, Copy)]
@@ -148,7 +149,17 @@ mod rustc {
             );
 
             let variant = adt_def.non_enum_variant();
-            let fields = c.to_valtree().unwrap_branch();
+            let fields = match c.try_to_valtree() {
+                Some(ValTree::Branch(branch)) => branch,
+                _ => {
+                    return Some(Self {
+                        alignment: true,
+                        lifetimes: true,
+                        safety: true,
+                        validity: true,
+                    });
+                }
+            };
 
             let get_field = |name| {
                 let (field_idx, _) = variant
diff --git a/compiler/rustc_ty_utils/src/needs_drop.rs b/compiler/rustc_ty_utils/src/needs_drop.rs
index 3e6dfc1304f..e173bba49be 100644
--- a/compiler/rustc_ty_utils/src/needs_drop.rs
+++ b/compiler/rustc_ty_utils/src/needs_drop.rs
@@ -96,7 +96,7 @@ where
                 return Some(Err(AlwaysRequiresDrop));
             }
 
-            let components = match needs_drop_components(ty, &tcx.data_layout) {
+            let components = match needs_drop_components(tcx, ty) {
                 Err(e) => return Some(Err(e)),
                 Ok(components) => components,
             };
@@ -160,7 +160,7 @@ where
                             queue_type(self, required);
                         }
                     }
-                    ty::Array(..) | ty::Alias(..) | ty::Param(_) => {
+                    ty::Alias(..) | ty::Array(..) | ty::Placeholder(_) | ty::Param(_) => {
                         if ty == component {
                             // Return the type to the caller: they may be able
                             // to normalize further than we can.
@@ -172,7 +172,31 @@ where
                             queue_type(self, component);
                         }
                     }
-                    _ => return Some(Err(AlwaysRequiresDrop)),
+
+                    ty::Foreign(_) | ty::Dynamic(..) => {
+                        return Some(Err(AlwaysRequiresDrop));
+                    }
+
+                    ty::Bool
+                    | ty::Char
+                    | ty::Int(_)
+                    | ty::Uint(_)
+                    | ty::Float(_)
+                    | ty::Str
+                    | ty::Slice(_)
+                    | ty::Ref(..)
+                    | ty::RawPtr(..)
+                    | ty::FnDef(..)
+                    | ty::FnPtr(..)
+                    | ty::Tuple(_)
+                    | ty::Bound(..)
+                    | ty::GeneratorWitness(..)
+                    | ty::GeneratorWitnessMIR(..)
+                    | ty::Never
+                    | ty::Infer(_)
+                    | ty::Error(_) => {
+                        bug!("unexpected type returned by `needs_drop_components`: {component}")
+                    }
                 }
             }
         }
diff --git a/compiler/rustc_ty_utils/src/ty.rs b/compiler/rustc_ty_utils/src/ty.rs
index f6302113e2a..505f78d0e5f 100644
--- a/compiler/rustc_ty_utils/src/ty.rs
+++ b/compiler/rustc_ty_utils/src/ty.rs
@@ -42,7 +42,7 @@ fn sized_constraint_for_ty<'tcx>(
             let adt_tys = adt.sized_constraint(tcx);
             debug!("sized_constraint_for_ty({:?}) intermediate = {:?}", ty, adt_tys);
             adt_tys
-                .arg_iter_copied(tcx, args)
+                .iter_instantiated_copied(tcx, args)
                 .flat_map(|ty| sized_constraint_for_ty(tcx, adtdef, ty))
                 .collect()
         }
@@ -297,7 +297,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ImplTraitInTraitFinder<'_, 'tcx> {
             for bound in self
                 .tcx
                 .item_bounds(unshifted_alias_ty.def_id)
-                .arg_iter(self.tcx, unshifted_alias_ty.args)
+                .iter_instantiated(self.tcx, unshifted_alias_ty.args)
             {
                 bound.visit_with(self);
             }
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index d287397aab3..5bf66850f03 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -604,6 +604,9 @@ pub mod alloc;
 // Private support modules
 mod panicking;
 
+#[unstable(feature = "ice_to_disk", issue = "none")]
+pub use panicking::panic_hook_with_disk_dump;
+
 #[path = "../../backtrace/src/lib.rs"]
 #[allow(dead_code, unused_attributes, fuzzy_provenance_casts)]
 mod backtrace_rs;
diff --git a/library/std/src/os/linux/raw.rs b/library/std/src/os/linux/raw.rs
index c55ca8ba26e..7c55e92502f 100644
--- a/library/std/src/os/linux/raw.rs
+++ b/library/std/src/os/linux/raw.rs
@@ -94,7 +94,7 @@ mod arch {
     }
 }
 
-#[cfg(target_arch = "mips")]
+#[cfg(any(target_arch = "mips", target_arch = "mips32r6"))]
 mod arch {
     use crate::os::raw::{c_long, c_ulong};
 
@@ -233,6 +233,7 @@ mod arch {
 #[cfg(any(
     target_arch = "loongarch64",
     target_arch = "mips64",
+    target_arch = "mips64r6",
     target_arch = "s390x",
     target_arch = "sparc64",
     target_arch = "riscv64",
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index a6a370409c0..0e90d618ad4 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -234,7 +234,16 @@ where
     *hook = Hook::Custom(Box::new(move |info| hook_fn(&prev, info)));
 }
 
+/// The default panic handler.
 fn default_hook(info: &PanicInfo<'_>) {
+    panic_hook_with_disk_dump(info, None)
+}
+
+#[unstable(feature = "ice_to_disk", issue = "none")]
+/// The implementation of the default panic handler.
+///
+/// It can also write the backtrace to a given `path`. This functionality is used only by `rustc`.
+pub fn panic_hook_with_disk_dump(info: &PanicInfo<'_>, path: Option<&crate::path::Path>) {
     // If this is a double panic, make sure that we print a backtrace
     // for this panic. Otherwise only print it if logging is enabled.
     let backtrace = if panic_count::get_count() >= 2 {
@@ -256,7 +265,7 @@ fn default_hook(info: &PanicInfo<'_>) {
     let thread = thread_info::current_thread();
     let name = thread.as_ref().and_then(|t| t.name()).unwrap_or("<unnamed>");
 
-    let write = |err: &mut dyn crate::io::Write| {
+    let write = |err: &mut dyn crate::io::Write, backtrace: Option<BacktraceStyle>| {
         let _ = writeln!(err, "thread '{name}' panicked at '{msg}', {location}");
 
         static FIRST_PANIC: AtomicBool = AtomicBool::new(true);
@@ -270,10 +279,19 @@ fn default_hook(info: &PanicInfo<'_>) {
             }
             Some(BacktraceStyle::Off) => {
                 if FIRST_PANIC.swap(false, Ordering::SeqCst) {
-                    let _ = writeln!(
-                        err,
-                        "note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace"
-                    );
+                    if let Some(path) = path {
+                        let _ = writeln!(
+                            err,
+                            "note: a backtrace for this error was stored at `{}`",
+                            path.display(),
+                        );
+                    } else {
+                        let _ = writeln!(
+                            err,
+                            "note: run with `RUST_BACKTRACE=1` environment variable to display a \
+                             backtrace"
+                        );
+                    }
                 }
             }
             // If backtraces aren't supported, do nothing.
@@ -281,11 +299,17 @@ fn default_hook(info: &PanicInfo<'_>) {
         }
     };
 
+    if let Some(path) = path
+        && let Ok(mut out) = crate::fs::File::options().create(true).write(true).open(&path)
+    {
+        write(&mut out, BacktraceStyle::full());
+    }
+
     if let Some(local) = set_output_capture(None) {
-        write(&mut *local.lock().unwrap_or_else(|e| e.into_inner()));
+        write(&mut *local.lock().unwrap_or_else(|e| e.into_inner()), backtrace);
         set_output_capture(Some(local));
     } else if let Some(mut out) = panic_output() {
-        write(&mut out);
+        write(&mut out, backtrace);
     }
 }
 
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 8f3201b0091..f9cb755b01a 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -558,6 +558,14 @@ impl Command {
     /// but this has some implementation limitations on Windows
     /// (see issue #37519).
     ///
+    /// # Platform-specific behavior
+    ///
+    /// Note on Windows: For executable files with the .exe extension,
+    /// it can be omitted when specifying the program for this Command.
+    /// However, if the file has a different extension,
+    /// a filename including the extension needs to be provided,
+    /// otherwise the file won't be found.
+    ///
     /// # Examples
     ///
     /// Basic usage:
diff --git a/library/std/src/sync/mpmc/utils.rs b/library/std/src/sync/mpmc/utils.rs
index d053d69e26e..0cbc61160f7 100644
--- a/library/std/src/sync/mpmc/utils.rs
+++ b/library/std/src/sync/mpmc/utils.rs
@@ -35,7 +35,9 @@ use crate::ops::{Deref, DerefMut};
     any(
         target_arch = "arm",
         target_arch = "mips",
+        target_arch = "mips32r6",
         target_arch = "mips64",
+        target_arch = "mips64r6",
         target_arch = "riscv64",
     ),
     repr(align(32))
@@ -59,7 +61,9 @@ use crate::ops::{Deref, DerefMut};
         target_arch = "powerpc64",
         target_arch = "arm",
         target_arch = "mips",
+        target_arch = "mips32r6",
         target_arch = "mips64",
+        target_arch = "mips64r6",
         target_arch = "riscv64",
         target_arch = "s390x",
     )),
diff --git a/library/std/src/sys/common/alloc.rs b/library/std/src/sys/common/alloc.rs
index a5fcbdf39c6..3ccea3ce0e3 100644
--- a/library/std/src/sys/common/alloc.rs
+++ b/library/std/src/sys/common/alloc.rs
@@ -9,6 +9,7 @@ use crate::ptr;
     target_arch = "arm",
     target_arch = "m68k",
     target_arch = "mips",
+    target_arch = "mips32r6",
     target_arch = "powerpc",
     target_arch = "powerpc64",
     target_arch = "sparc",
@@ -24,6 +25,7 @@ pub const MIN_ALIGN: usize = 8;
     target_arch = "aarch64",
     target_arch = "loongarch64",
     target_arch = "mips64",
+    target_arch = "mips64r6",
     target_arch = "s390x",
     target_arch = "sparc64",
     target_arch = "riscv64",
diff --git a/library/std/src/sys/personality/gcc.rs b/library/std/src/sys/personality/gcc.rs
index 6552d96ca69..dc9636ac8c9 100644
--- a/library/std/src/sys/personality/gcc.rs
+++ b/library/std/src/sys/personality/gcc.rs
@@ -59,7 +59,12 @@ const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1 / X0, X1
 #[cfg(target_arch = "m68k")]
 const UNWIND_DATA_REG: (i32, i32) = (0, 1); // D0, D1
 
-#[cfg(any(target_arch = "mips", target_arch = "mips64"))]
+#[cfg(any(
+    target_arch = "mips",
+    target_arch = "mips32r6",
+    target_arch = "mips64",
+    target_arch = "mips64r6"
+))]
 const UNWIND_DATA_REG: (i32, i32) = (4, 5); // A0, A1
 
 #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
diff --git a/library/unwind/src/libunwind.rs b/library/unwind/src/libunwind.rs
index ec24e137572..521da6c4589 100644
--- a/library/unwind/src/libunwind.rs
+++ b/library/unwind/src/libunwind.rs
@@ -51,10 +51,10 @@ pub const unwinder_private_data_size: usize = 5;
 #[cfg(target_arch = "m68k")]
 pub const unwinder_private_data_size: usize = 2;
 
-#[cfg(target_arch = "mips")]
+#[cfg(any(target_arch = "mips", target_arch = "mips32r6"))]
 pub const unwinder_private_data_size: usize = 2;
 
-#[cfg(target_arch = "mips64")]
+#[cfg(any(target_arch = "mips64", target_arch = "mips64r6"))]
 pub const unwinder_private_data_size: usize = 2;
 
 #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index 766c187e8e8..32eb4e68b08 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -1629,6 +1629,7 @@ impl<'a> Builder<'a> {
         // fun to pass a flag to a tool to pass a flag to pass a flag to a tool
         // to change a flag in a binary?
         if self.config.rpath_enabled(target) && util::use_host_linker(target) {
+            let libdir = self.sysroot_libdir_relative(compiler).to_str().unwrap();
             let rpath = if target.contains("apple") {
                 // Note that we need to take one extra step on macOS to also pass
                 // `-Wl,-instal_name,@rpath/...` to get things to work right. To
@@ -1636,10 +1637,10 @@ impl<'a> Builder<'a> {
                 // so. Note that this is definitely a hack, and we should likely
                 // flesh out rpath support more fully in the future.
                 rustflags.arg("-Zosx-rpath-install-name");
-                Some("-Wl,-rpath,@loader_path/../lib")
+                Some(format!("-Wl,-rpath,@loader_path/../{}", libdir))
             } else if !target.contains("windows") && !target.contains("aix") {
                 rustflags.arg("-Clink-args=-Wl,-z,origin");
-                Some("-Wl,-rpath,$ORIGIN/../lib")
+                Some(format!("-Wl,-rpath,$ORIGIN/../{}", libdir))
             } else {
                 None
             };
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index de43a401926..059eb9ffc7b 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -133,7 +133,12 @@ const EXTRA_CHECK_CFGS: &[(Option<Mode>, &'static str, Option<&[&'static str]>)]
     /* Extra values not defined in the built-in targets yet, but used in std */
     (Some(Mode::Std), "target_env", Some(&["libnx"])),
     // (Some(Mode::Std), "target_os", Some(&[])),
-    (Some(Mode::Std), "target_arch", Some(&["asmjs", "spirv", "nvptx", "xtensa"])),
+    // #[cfg(bootstrap)] mips32r6, mips64r6
+    (
+        Some(Mode::Std),
+        "target_arch",
+        Some(&["asmjs", "spirv", "nvptx", "xtensa", "mips32r6", "mips64r6"]),
+    ),
     /* Extra names used by dependencies */
     // FIXME: Used by serde_json, but we should not be triggering on external dependencies.
     (Some(Mode::Rustc), "no_btreemap_remove_entry", None),
diff --git a/src/etc/htmldocck.py b/src/etc/htmldocck.py
index 5ab1874e9ed..2e0f832192f 100755
--- a/src/etc/htmldocck.py
+++ b/src/etc/htmldocck.py
@@ -274,6 +274,8 @@ def get_commands(template):
                 args = shlex.split(args)
             except UnicodeEncodeError:
                 args = [arg.decode('utf-8') for arg in shlex.split(args.encode('utf-8'))]
+            except Exception as exc:
+                raise Exception("line {}: {}".format(lineno + 1, exc)) from None
             yield Command(negated=negated, cmd=cmd, args=args, lineno=lineno+1, context=line)
 
 
diff --git a/src/librustdoc/clean/cfg.rs b/src/librustdoc/clean/cfg.rs
index 5177cffe6ba..83886dd42aa 100644
--- a/src/librustdoc/clean/cfg.rs
+++ b/src/librustdoc/clean/cfg.rs
@@ -520,7 +520,9 @@ impl<'a> fmt::Display for Display<'a> {
                         "loongarch64" => "LoongArch LA64",
                         "m68k" => "M68k",
                         "mips" => "MIPS",
+                        "mips32r6" => "MIPS Release 6",
                         "mips64" => "MIPS-64",
+                        "mips64r6" => "MIPS-64 Release 6",
                         "msp430" => "MSP430",
                         "powerpc" => "PowerPC",
                         "powerpc64" => "PowerPC-64",
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index c4596140fb6..d14953f1bb7 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -90,6 +90,19 @@ pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<
         }
         v
     }));
+    items.extend(doc.inlined_foreigns.iter().flat_map(|((_, renamed), (res, local_import_id))| {
+        let Some(def_id) = res.opt_def_id() else { return Vec::new() };
+        let name = renamed.unwrap_or_else(|| cx.tcx.item_name(def_id));
+        let import = cx.tcx.hir().expect_item(*local_import_id);
+        match import.kind {
+            hir::ItemKind::Use(path, kind) => {
+                let hir::UsePath { segments, span, .. } = *path;
+                let path = hir::Path { segments, res: *res, span };
+                clean_use_statement_inner(import, name, &path, kind, cx, &mut Default::default())
+            }
+            _ => unreachable!(),
+        }
+    }));
     items.extend(doc.items.values().flat_map(|(item, renamed, _)| {
         // Now we actually lower the imports, skipping everything else.
         if let hir::ItemKind::Use(path, hir::UseKind::Glob) = item.kind {
@@ -441,7 +454,7 @@ fn clean_projection<'tcx>(
         let bounds = cx
             .tcx
             .explicit_item_bounds(ty.skip_binder().def_id)
-            .arg_iter_copied(cx.tcx, ty.skip_binder().args)
+            .iter_instantiated_copied(cx.tcx, ty.skip_binder().args)
             .map(|(pred, _)| pred)
             .collect::<Vec<_>>();
         return clean_middle_opaque_bounds(cx, bounds);
@@ -2071,7 +2084,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
                 let bounds = cx
                     .tcx
                     .explicit_item_bounds(def_id)
-                    .arg_iter_copied(cx.tcx, args)
+                    .iter_instantiated_copied(cx.tcx, args)
                     .map(|(bound, _)| bound)
                     .collect::<Vec<_>>();
                 let ty = clean_middle_opaque_bounds(cx, bounds);
@@ -2652,9 +2665,6 @@ fn clean_use_statement<'tcx>(
     let mut items = Vec::new();
     let hir::UsePath { segments, ref res, span } = *path;
     for &res in res {
-        if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = res {
-            continue;
-        }
         let path = hir::Path { segments, res, span };
         items.append(&mut clean_use_statement_inner(import, name, &path, kind, cx, inlined_names));
     }
@@ -2669,6 +2679,9 @@ fn clean_use_statement_inner<'tcx>(
     cx: &mut DocContext<'tcx>,
     inlined_names: &mut FxHashSet<(ItemType, Symbol)>,
 ) -> Vec<Item> {
+    if let Res::Def(DefKind::Ctor(..), _) | Res::SelfCtor(..) = path.res {
+        return Vec::new();
+    }
     // We need this comparison because some imports (for std types for example)
     // are "inserted" as well but directly by the compiler and they should not be
     // taken into account.
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 82a1fe310b3..7fb069d6e70 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -176,6 +176,7 @@ pub(crate) fn new_handler(
     rustc_errors::Handler::with_emitter_and_flags(
         emitter,
         unstable_opts.diagnostic_handler_flags(true),
+        None,
     )
 }
 
@@ -296,6 +297,7 @@ pub(crate) fn create_config(
         }),
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
+        ice_file: None,
     }
 }
 
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 6047cf23350..6766dcba18a 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -108,6 +108,7 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
         override_queries: None,
         make_codegen_backend: None,
         registry: rustc_driver::diagnostics_registry(),
+        ice_file: None,
     };
 
     let test_args = options.test_args.clone();
@@ -586,7 +587,7 @@ pub(crate) fn make_test(
             );
 
             // FIXME(misdreavus): pass `-Z treat-err-as-bug` to the doctest parser
-            let handler = Handler::with_emitter(false, None, Box::new(emitter));
+            let handler = Handler::with_emitter(false, None, Box::new(emitter), None);
             let sess = ParseSess::with_span_handler(handler, sm);
 
             let mut found_main = false;
@@ -773,7 +774,7 @@ fn check_if_attr_is_complete(source: &str, edition: Edition) -> bool {
                 TerminalUrl::No,
             );
 
-            let handler = Handler::with_emitter(false, None, Box::new(emitter));
+            let handler = Handler::with_emitter(false, None, Box::new(emitter), None);
             let sess = ParseSess::with_span_handler(handler, sm);
             let mut parser =
                 match maybe_new_parser_from_source_str(&sess, filename, source.to_owned()) {
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 9209915895a..94e778406f8 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -888,7 +888,7 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	justify-content: start;
 	flex: 3;
 }
-.search-results .result-name span.alias {
+.search-results .result-name .alias {
 	color: var(--search-results-alias-color);
 }
 .search-results .result-name .grey {
@@ -904,6 +904,9 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	max-width: calc(100% - var(--search-typename-width));
 	display: inline-block;
 }
+.search-results .result-name .path > * {
+	display: inline;
+}
 
 .popover {
 	position: absolute;
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 51d8e81ca86..42088e73554 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -2108,29 +2108,22 @@ function initSearch(rawSearchIndex) {
                 const resultName = document.createElement("div");
                 resultName.className = "result-name";
 
-                if (item.is_alias) {
-                    const alias = document.createElement("span");
-                    alias.className = "alias";
-
-                    const bold = document.createElement("b");
-                    bold.innerText = item.alias;
-                    alias.appendChild(bold);
-
-                    alias.insertAdjacentHTML(
-                        "beforeend",
-                        "<i class=\"grey\">&nbsp;- see&nbsp;</i>");
+                resultName.insertAdjacentHTML(
+                    "beforeend",
+                    `<span class="typename">${typeName}</span>`);
+                link.appendChild(resultName);
 
-                    resultName.appendChild(alias);
+                let alias = " ";
+                if (item.is_alias) {
+                    alias = ` <div class="alias">\
+<b>${item.alias}</b><i class="grey">&nbsp;- see&nbsp;</i>\
+</div>`;
                 }
-
                 resultName.insertAdjacentHTML(
                     "beforeend",
-                    `\
-<span class="typename">${typeName}</span>\
-<div class="path">\
- ${item.displayPath}<span class="${type}">${name}</span>\
+                    `<div class="path">${alias}\
+${item.displayPath}<span class="${type}">${name}</span>\
 </div>`);
-                link.appendChild(resultName);
 
                 const description = document.createElement("div");
                 description.className = "desc";
diff --git a/src/librustdoc/passes/lint/check_code_block_syntax.rs b/src/librustdoc/passes/lint/check_code_block_syntax.rs
index 369a8069593..c82f2bc987a 100644
--- a/src/librustdoc/passes/lint/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/lint/check_code_block_syntax.rs
@@ -40,7 +40,7 @@ fn check_rust_syntax(
     let emitter = BufferEmitter { buffer: Lrc::clone(&buffer), fallback_bundle };
 
     let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
-    let handler = Handler::with_emitter(false, None, Box::new(emitter));
+    let handler = Handler::with_emitter(false, None, Box::new(emitter), None);
     let source = dox[code_block.code].to_owned();
     let sess = ParseSess::with_span_handler(handler, sm);
 
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 265123ddf6c..66737a01521 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -35,6 +35,8 @@ pub(crate) struct Module<'hir> {
         (LocalDefId, Option<Symbol>),
         (&'hir hir::Item<'hir>, Option<Symbol>, Option<LocalDefId>),
     >,
+    /// Same as for `items`.
+    pub(crate) inlined_foreigns: FxIndexMap<(DefId, Option<Symbol>), (Res, LocalDefId)>,
     pub(crate) foreigns: Vec<(&'hir hir::ForeignItem<'hir>, Option<Symbol>)>,
 }
 
@@ -54,6 +56,7 @@ impl Module<'_> {
             import_id,
             mods: Vec::new(),
             items: FxIndexMap::default(),
+            inlined_foreigns: FxIndexMap::default(),
             foreigns: Vec::new(),
         }
     }
@@ -272,21 +275,30 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             return false;
         }
 
-        // For cross-crate impl inlining we need to know whether items are
-        // reachable in documentation -- a previously unreachable item can be
-        // made reachable by cross-crate inlining which we're checking here.
-        // (this is done here because we need to know this upfront).
-        if !ori_res_did.is_local() && !is_no_inline {
-            crate::visit_lib::lib_embargo_visit_item(self.cx, ori_res_did);
-            return false;
-        }
-
+        let is_hidden = !document_hidden && tcx.is_doc_hidden(ori_res_did);
         let Some(res_did) = ori_res_did.as_local() else {
-            return false;
+            // For cross-crate impl inlining we need to know whether items are
+            // reachable in documentation -- a previously unreachable item can be
+            // made reachable by cross-crate inlining which we're checking here.
+            // (this is done here because we need to know this upfront).
+            crate::visit_lib::lib_embargo_visit_item(self.cx, ori_res_did);
+            if is_hidden {
+                return false;
+            }
+            // We store inlined foreign items otherwise, it'd mean that the `use` item would be kept
+            // around. It's not a problem unless this `use` imports both a local AND a foreign item.
+            // If a local item is inlined, its `use` is not supposed to still be around in `clean`,
+            // which would make appear the `use` in the generated documentation like the local item
+            // was not inlined even though it actually was.
+            self.modules
+                .last_mut()
+                .unwrap()
+                .inlined_foreigns
+                .insert((ori_res_did, renamed), (res, def_id));
+            return true;
         };
 
         let is_private = !self.cx.cache.effective_visibilities.is_directly_public(tcx, ori_res_did);
-        let is_hidden = !document_hidden && tcx.is_doc_hidden(ori_res_did);
         let item = tcx.hir().get_by_def_id(res_did);
 
         if !please_inline {
@@ -314,7 +326,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             return false;
         }
 
-        let inlined = match tcx.hir().get_by_def_id(res_did) {
+        let inlined = match item {
             // Bang macros are handled a bit on their because of how they are handled by the
             // compiler. If they have `#[doc(hidden)]` and the re-export doesn't have
             // `#[doc(inline)]`, then we don't inline it.
@@ -346,7 +358,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         };
         self.view_item_stack.remove(&res_did);
         if inlined {
-            self.cx.cache.inlined_items.insert(res_did.to_def_id());
+            self.cx.cache.inlined_items.insert(ori_res_did);
         }
         inlined
     }
@@ -483,7 +495,6 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                             continue;
                         }
                     }
-
                     self.add_to_current_mod(item, renamed, import_id);
                 }
             }
diff --git a/src/tools/cargo b/src/tools/cargo
-Subproject 694a579566a9a1482b20aff8a68f0e4edd99bd2
+Subproject 1b15556767f4b78a64e868eedf4073c423f02b9
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
index e5f39d102cd..8879c529262 100644
--- a/src/tools/clippy/clippy_lints/src/doc.rs
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -729,7 +729,7 @@ fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
                     false,
                     TerminalUrl::No,
                 );
-                let handler = Handler::with_emitter(false, None, Box::new(emitter));
+                let handler = Handler::with_emitter(false, None, Box::new(emitter), None);
                 let sess = ParseSess::with_span_handler(handler, sm);
 
                 let mut parser = match maybe_new_parser_from_source_str(&sess, filename, code) {
diff --git a/src/tools/clippy/clippy_lints/src/future_not_send.rs b/src/tools/clippy/clippy_lints/src/future_not_send.rs
index e54429aee8e..621415c881c 100644
--- a/src/tools/clippy/clippy_lints/src/future_not_send.rs
+++ b/src/tools/clippy/clippy_lints/src/future_not_send.rs
@@ -66,7 +66,7 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
         if let ty::Alias(ty::Opaque, AliasTy { def_id, args, .. }) = *ret_ty.kind() {
             let preds = cx.tcx.explicit_item_bounds(def_id);
             let mut is_future = false;
-            for (p, _span) in preds.arg_iter_copied(cx.tcx, args) {
+            for (p, _span) in preds.iter_instantiated_copied(cx.tcx, args) {
                 if let Some(trait_pred) = p.as_trait_clause() {
                     if Some(trait_pred.skip_binder().trait_ref.def_id) == cx.tcx.lang_items().future_trait() {
                         is_future = true;
diff --git a/src/tools/clippy/clippy_utils/src/ty.rs b/src/tools/clippy/clippy_utils/src/ty.rs
index ad79143f4da..fd39a246f48 100644
--- a/src/tools/clippy/clippy_utils/src/ty.rs
+++ b/src/tools/clippy/clippy_utils/src/ty.rs
@@ -663,7 +663,7 @@ pub fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'t
         ty::Alias(ty::Opaque, ty::AliasTy { def_id, args, .. }) => sig_from_bounds(
             cx,
             ty,
-            cx.tcx.item_bounds(def_id).arg_iter(cx.tcx, args),
+            cx.tcx.item_bounds(def_id).iter_instantiated(cx.tcx, args),
             cx.tcx.opt_parent(def_id),
         ),
         ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig, None)),
@@ -739,7 +739,7 @@ fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: AliasTy<'tcx>) -> Option
     let mut output = None;
     let lang_items = cx.tcx.lang_items();
 
-    for (pred, _) in cx.tcx.explicit_item_bounds(ty.def_id).arg_iter_copied(cx.tcx, ty.args) {
+    for (pred, _) in cx.tcx.explicit_item_bounds(ty.def_id).iter_instantiated_copied(cx.tcx, ty.args) {
         match pred.kind().skip_binder() {
             ty::ClauseKind::Trait(p)
                 if (lang_items.fn_trait() == Some(p.def_id())
diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index d67e9aaaa6e..4ae2249097f 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -232,7 +232,7 @@ impl TestProps {
             aux_builds: vec![],
             aux_crates: vec![],
             revisions: vec![],
-            rustc_env: vec![],
+            rustc_env: vec![("RUSTC_ICE".to_string(), "0".to_string())],
             unset_rustc_env: vec![],
             exec_env: vec![],
             unset_exec_env: vec![],
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index b91e1b09330..7eeb987063f 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -4149,8 +4149,8 @@ impl<'test> TestCx<'test> {
                   # Match paths that don't include spaces.
                   (?:\\[\pL\pN\.\-_']+)+\.\pL+
                 |
-                  # If the path starts with a well-known root, then allow spaces.
-                  \$(?:DIR|SRC_DIR|TEST_BUILD_DIR|BUILD_DIR|LIB_DIR)(?:\\[\pL\pN\.\-_' ]+)+
+                  # If the path starts with a well-known root, then allow spaces and no file extension.
+                  \$(?:DIR|SRC_DIR|TEST_BUILD_DIR|BUILD_DIR|LIB_DIR)(?:\\[\pL\pN\.\-_'\ ]+)+
                 )"#,
             )
             .unwrap()
diff --git a/src/tools/compiletest/src/runtest/tests.rs b/src/tools/compiletest/src/runtest/tests.rs
index 51105111175..fb3dd326a4c 100644
--- a/src/tools/compiletest/src/runtest/tests.rs
+++ b/src/tools/compiletest/src/runtest/tests.rs
@@ -8,8 +8,8 @@ fn normalize_platform_differences() {
         "$BUILD_DIR/../parser.rs"
     );
     assert_eq!(
-        TestCx::normalize_platform_differences(r"$DIR\bar.rs hello\nworld"),
-        r"$DIR/bar.rs hello\nworld"
+        TestCx::normalize_platform_differences(r"$DIR\bar.rs: hello\nworld"),
+        r"$DIR/bar.rs: hello\nworld"
     );
     assert_eq!(
         TestCx::normalize_platform_differences(r"either bar\baz.rs or bar\baz\mod.rs"),
@@ -27,8 +27,8 @@ fn normalize_platform_differences() {
     );
     assert_eq!(TestCx::normalize_platform_differences(r"$DIR\foo.rs:12:11"), "$DIR/foo.rs:12:11",);
     assert_eq!(
-        TestCx::normalize_platform_differences(r"$DIR\path with spaces 'n' quotes"),
-        "$DIR/path with spaces 'n' quotes",
+        TestCx::normalize_platform_differences(r"$DIR\path with\spaces 'n' quotes"),
+        "$DIR/path with/spaces 'n' quotes",
     );
     assert_eq!(
         TestCx::normalize_platform_differences(r"$DIR\file_with\no_extension"),
diff --git a/src/tools/miri/rust-version b/src/tools/miri/rust-version
index 2cc690989d1..da89b71ccd5 100644
--- a/src/tools/miri/rust-version
+++ b/src/tools/miri/rust-version
@@ -1 +1 @@
-ec362f0ae8a05618b75727cfdca853540cb2950e
+0646a5d1aa3745cb448db247f6fa432890a1812b
diff --git a/src/tools/miri/src/shims/foreign_items.rs b/src/tools/miri/src/shims/foreign_items.rs
index 6915c396d61..72a4adba8d4 100644
--- a/src/tools/miri/src/shims/foreign_items.rs
+++ b/src/tools/miri/src/shims/foreign_items.rs
@@ -45,8 +45,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // List taken from `library/std/src/sys/common/alloc.rs`.
         // This list should be kept in sync with the one from libstd.
         let min_align = match this.tcx.sess.target.arch.as_ref() {
-            "x86" | "arm" | "mips" | "powerpc" | "powerpc64" | "asmjs" | "wasm32" => 8,
-            "x86_64" | "aarch64" | "mips64" | "s390x" | "sparc64" | "loongarch64" => 16,
+            "x86" | "arm" | "mips" | "mips32r6" | "powerpc" | "powerpc64" | "asmjs" | "wasm32" => 8,
+            "x86_64" | "aarch64" | "mips64" | "mips64r6" | "s390x" | "sparc64" | "loongarch64" =>
+                16,
             arch => bug!("unsupported target architecture for malloc: `{}`", arch),
         };
         // Windows always aligns, even small allocations.
diff --git a/src/tools/miri/tests/fail/layout_cycle.stderr b/src/tools/miri/tests/fail/layout_cycle.stderr
index 62b7d5fb77d..38907a1c50c 100644
--- a/src/tools/miri/tests/fail/layout_cycle.stderr
+++ b/src/tools/miri/tests/fail/layout_cycle.stderr
@@ -2,6 +2,7 @@ error[E0391]: cycle detected when computing layout of `S<S<()>>`
    |
    = note: ...which requires computing layout of `<S<()> as Tr>::I`...
    = note: ...which again requires computing layout of `S<S<()>>`, completing the cycle
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: post-monomorphization error: a cycle occurred during layout computation
   --> RUSTLIB/core/src/mem/mod.rs:LL:CC
diff --git a/src/tools/rustfmt/src/parse/session.rs b/src/tools/rustfmt/src/parse/session.rs
index 81b5015dde3..92d2425cd3b 100644
--- a/src/tools/rustfmt/src/parse/session.rs
+++ b/src/tools/rustfmt/src/parse/session.rs
@@ -162,6 +162,7 @@ fn default_handler(
             ignore_path_set,
             can_reset,
         }),
+        None,
     )
 }
 
@@ -233,7 +234,7 @@ impl ParseSess {
     }
 
     pub(crate) fn set_silent_emitter(&mut self) {
-        self.parse_sess.span_diagnostic = Handler::with_emitter(true, None, silent_emitter());
+        self.parse_sess.span_diagnostic = Handler::with_emitter(true, None, silent_emitter(), None);
     }
 
     pub(crate) fn span_to_filename(&self, span: Span) -> FileName {
diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 9f0f0d86c8b..2be369d2b74 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -253,6 +253,9 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "thiserror-impl",
     "thorin-dwp",
     "thread_local",
+    "time",
+    "time-core",
+    "time-macros",
     "tinystr",
     "tinyvec",
     "tinyvec_macros",
diff --git a/tests/codegen/no_builtins-at-crate.rs b/tests/codegen/no_builtins-at-crate.rs
new file mode 100644
index 00000000000..02ed670900e
--- /dev/null
+++ b/tests/codegen/no_builtins-at-crate.rs
@@ -0,0 +1,24 @@
+// compile-flags: -C opt-level=1
+
+#![no_builtins]
+#![crate_type = "lib"]
+
+// CHECK: define
+// CHECK-SAME: @__aeabi_memcpy
+// CHECK-SAME: #0
+#[no_mangle]
+pub unsafe extern "C" fn __aeabi_memcpy(dest: *mut u8, src: *const u8, size: usize) {
+    // CHECK: call
+    // CHECK-SAME: @memcpy(
+    memcpy(dest, src, size);
+}
+
+// CHECK: declare
+// CHECK-SAME: @memcpy
+// CHECK-SAME: #0
+extern "C" {
+    pub fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8;
+}
+
+// CHECK: attributes #0
+// CHECK-SAME: "no-builtins"
diff --git a/tests/run-make-fulldeps/issue-19371/foo.rs b/tests/run-make-fulldeps/issue-19371/foo.rs
index d4959247d1c..68132638759 100644
--- a/tests/run-make-fulldeps/issue-19371/foo.rs
+++ b/tests/run-make-fulldeps/issue-19371/foo.rs
@@ -52,6 +52,7 @@ fn compile(code: String, output: PathBuf, sysroot: PathBuf) {
         input,
         output_file: Some(OutFileName::Real(output)),
         output_dir: None,
+        ice_file: None,
         file_loader: None,
         locale_resources: &[],
         lint_caps: Default::default(),
diff --git a/tests/run-make/dump-ice-to-disk/Makefile b/tests/run-make/dump-ice-to-disk/Makefile
new file mode 100644
index 00000000000..4f33d590237
--- /dev/null
+++ b/tests/run-make/dump-ice-to-disk/Makefile
@@ -0,0 +1,9 @@
+include ../tools.mk
+
+# ignore-windows
+
+export RUSTC := $(RUSTC_ORIGINAL)
+export TMPDIR := $(TMPDIR)
+
+all:
+	bash check.sh
diff --git a/tests/run-make/dump-ice-to-disk/check.sh b/tests/run-make/dump-ice-to-disk/check.sh
new file mode 100644
index 00000000000..91109596a45
--- /dev/null
+++ b/tests/run-make/dump-ice-to-disk/check.sh
@@ -0,0 +1,58 @@
+#!/bin/sh
+
+# Default nightly behavior (write ICE to current directory)
+# FIXME(estebank): these are failing on CI, but passing locally.
+# $RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-default.log 2>&1
+# default=$(cat ./rustc-ice-*.txt | wc -l)
+# rm ./rustc-ice-*.txt
+
+# Explicit directory set
+export RUSTC_ICE=$TMPDIR
+$RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-default-set.log 2>&1
+default_set=$(cat $TMPDIR/rustc-ice-*.txt | wc -l)
+content=$(cat $TMPDIR/rustc-ice-*.txt)
+rm $TMPDIR/rustc-ice-*.txt
+RUST_BACKTRACE=short $RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-short.log 2>&1
+short=$(cat $TMPDIR/rustc-ice-*.txt | wc -l)
+rm $TMPDIR/rustc-ice-*.txt
+RUST_BACKTRACE=full $RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-full.log 2>&1
+full=$(cat $TMPDIR/rustc-ice-*.txt | wc -l)
+rm $TMPDIR/rustc-ice-*.txt
+
+# Explicitly disabling ICE dump
+export RUSTC_ICE=0
+$RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-disabled.log 2>&1
+should_be_empty_tmp=$(ls -l $TMPDIR/rustc-ice-*.txt | wc -l)
+should_be_empty_dot=$(ls -l ./rustc-ice-*.txt | wc -l)
+
+echo "#### ICE Dump content:"
+echo $content
+echo "#### default length:"
+echo $default
+echo "#### short length:"
+echo $short
+echo "#### default_set length:"
+echo $default_set
+echo "#### full length:"
+echo $full
+echo "#### should_be_empty_dot length:"
+echo $should_be_empty_dot
+echo "#### should_be_empty_tmp length:"
+echo $should_be_empty_tmp
+
+## Verify that a the ICE dump file is created in the appropriate directories, that
+## their lengths are the same regardless of other backtrace configuration options,
+## that the file is not created when asked to (RUSTC_ICE=0) and that the file
+## contains at least part of the expected content.
+if [ $short -eq $default_set ] &&
+    #[ $default -eq $short ] &&
+    [ $default_set -eq $full ] &&
+    [[ $content == *"thread 'rustc' panicked at "* ]] &&
+    [[ $content == *"stack backtrace:"* ]] &&
+    #[ $default -gt 0 ] &&
+    [ $should_be_empty_dot -eq 0 ] &&
+    [ $should_be_empty_tmp -eq 0 ]; then
+    exit 0
+else
+    exit 1
+fi
diff --git a/tests/run-make/dump-ice-to-disk/src/lib.rs b/tests/run-make/dump-ice-to-disk/src/lib.rs
new file mode 100644
index 00000000000..b23b7f830d7
--- /dev/null
+++ b/tests/run-make/dump-ice-to-disk/src/lib.rs
@@ -0,0 +1,7 @@
+fn func(s: &str) {
+    println!("{}", s);
+}
+
+fn main() {
+    func(1);
+}
diff --git a/tests/run-make/exit-code/Makefile b/tests/run-make/exit-code/Makefile
index 6458b71688f..155e5cd1123 100644
--- a/tests/run-make/exit-code/Makefile
+++ b/tests/run-make/exit-code/Makefile
@@ -5,7 +5,7 @@ all:
 	$(RUSTC) success.rs; [ $$? -eq 0 ]
 	$(RUSTC) --invalid-arg-foo; [ $$? -eq 1 ]
 	$(RUSTC) compile-error.rs; [ $$? -eq 1 ]
-	$(RUSTC) -Ztreat-err-as-bug compile-error.rs; [ $$? -eq 101 ]
+	RUSTC_ICE=0 $(RUSTC) -Ztreat-err-as-bug compile-error.rs; [ $$? -eq 101 ]
 	$(RUSTDOC) -o $(TMPDIR)/exit-code success.rs; [ $$? -eq 0 ]
 	$(RUSTDOC) --invalid-arg-foo; [ $$? -eq 1 ]
 	$(RUSTDOC) compile-error.rs; [ $$? -eq 1 ]
diff --git a/tests/run-make/no-builtins-attribute/Makefile b/tests/run-make/no-builtins-attribute/Makefile
new file mode 100644
index 00000000000..0ce95facaea
--- /dev/null
+++ b/tests/run-make/no-builtins-attribute/Makefile
@@ -0,0 +1,9 @@
+include ../tools.mk
+
+# We want to check if `no-builtins` is also added to the function declarations in the used crate.
+
+all:
+	$(RUSTC) no_builtins.rs --emit=link
+	$(RUSTC) main.rs --emit=llvm-ir
+
+	cat "$(TMPDIR)"/main.ll | "$(LLVM_FILECHECK)" filecheck.main.txt
diff --git a/tests/run-make/no-builtins-attribute/filecheck.main.txt b/tests/run-make/no-builtins-attribute/filecheck.main.txt
new file mode 100644
index 00000000000..ecd650bdca8
--- /dev/null
+++ b/tests/run-make/no-builtins-attribute/filecheck.main.txt
@@ -0,0 +1,5 @@
+CHECK: declare void @foo()
+CHECK-SAME: #[[ATTR_3:[0-9]+]]
+
+CHECK: attributes #[[ATTR_3]] 
+CHECK-SAME: no-builtins
diff --git a/tests/run-make/no-builtins-attribute/main.rs b/tests/run-make/no-builtins-attribute/main.rs
new file mode 100644
index 00000000000..77754b37e31
--- /dev/null
+++ b/tests/run-make/no-builtins-attribute/main.rs
@@ -0,0 +1,10 @@
+extern crate no_builtins;
+
+#[no_mangle]
+fn call_foo() {
+    no_builtins::foo();
+}
+
+fn main() {
+    call_foo();
+}
diff --git a/tests/run-make/no-builtins-attribute/no_builtins.rs b/tests/run-make/no-builtins-attribute/no_builtins.rs
new file mode 100644
index 00000000000..8ca862d2f77
--- /dev/null
+++ b/tests/run-make/no-builtins-attribute/no_builtins.rs
@@ -0,0 +1,5 @@
+#![crate_type = "lib"]
+#![no_builtins]
+
+#[no_mangle]
+pub fn foo() {}
diff --git a/tests/run-make/short-ice/check.sh b/tests/run-make/short-ice/check.sh
index a13b7eeca8f..56babd2142f 100644
--- a/tests/run-make/short-ice/check.sh
+++ b/tests/run-make/short-ice/check.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-
+export RUSTC_ICE=0
 RUST_BACKTRACE=1 $RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-1.log 2>&1
 RUST_BACKTRACE=full $RUSTC src/lib.rs -Z treat-err-as-bug=1 1>$TMPDIR/rust-test-2.log 2>&1
 
diff --git a/tests/rustdoc-gui/search-reexport.goml b/tests/rustdoc-gui/search-reexport.goml
index 6ea6d53e287..b9d2c8f15ce 100644
--- a/tests/rustdoc-gui/search-reexport.goml
+++ b/tests/rustdoc-gui/search-reexport.goml
@@ -26,7 +26,7 @@ write: (".search-input", "AliasForTheStdReexport")
 wait-for: "//a[@class='result-import']"
 assert-text: (
     "a.result-import .result-name",
-    "AliasForTheStdReexport - see re-export test_docs::TheStdReexport",
+    "re-export AliasForTheStdReexport - see test_docs::TheStdReexport",
 )
 // Same thing again, we click on it to ensure the background is once again set as expected.
 click: "//a[@class='result-import']"
diff --git a/tests/rustdoc-gui/search-result-color.goml b/tests/rustdoc-gui/search-result-color.goml
index 7a7785fd9ac..f9f81c5ba04 100644
--- a/tests/rustdoc-gui/search-result-color.goml
+++ b/tests/rustdoc-gui/search-result-color.goml
@@ -368,8 +368,8 @@ define-function: (
         // Waiting for the search results to appear...
         wait-for: "#search-tabs"
         // Checking that the colors for the alias element are the ones expected.
-        assert-css: (".result-name > .alias", {"color": |alias|})
-        assert-css: (".result-name > .alias > .grey", {"color": |grey|})
+        assert-css: (".result-name .path .alias", {"color": |alias|})
+        assert-css: (".result-name .path .alias > .grey", {"color": |grey|})
         // Leave the search results to prevent reloading with an already filled search input.
         press-key: "Escape"
     },
diff --git a/tests/rustdoc-ui/ice-bug-report-url.rs b/tests/rustdoc-ui/ice-bug-report-url.rs
index 8ede91cf8f4..7689d78d31f 100644
--- a/tests/rustdoc-ui/ice-bug-report-url.rs
+++ b/tests/rustdoc-ui/ice-bug-report-url.rs
@@ -1,4 +1,5 @@
 // compile-flags: -Ztreat-err-as-bug
+// rustc-env:RUSTC_ICE=0
 // failure-status: 101
 // error-pattern: aborting due to
 // error-pattern: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-rustdoc&template=ice.md
diff --git a/tests/rustdoc-ui/ice-bug-report-url.stderr b/tests/rustdoc-ui/ice-bug-report-url.stderr
index 98c08b9a894..7d9f05f8f4e 100644
--- a/tests/rustdoc-ui/ice-bug-report-url.stderr
+++ b/tests/rustdoc-ui/ice-bug-report-url.stderr
@@ -1,5 +1,5 @@
 error: expected one of `->`, `where`, or `{`, found `<eof>`
-  --> $DIR/ice-bug-report-url.rs:13:10
+  --> $DIR/ice-bug-report-url.rs:14:10
    |
 LL | fn wrong()
    |          ^ expected one of `->`, `where`, or `{`
diff --git a/tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr b/tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr
index 79e1b753112..9aeb3389e2d 100644
--- a/tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr
+++ b/tests/rustdoc-ui/issue-110629-private-type-cycle-dyn.stderr
@@ -19,6 +19,7 @@ LL | | fn bar<'a, 'b>(i: &'a i32) -> Bar<'a, 'b> {
 LL | |     assert!(bar(&meh) == bar(&muh));
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/rustdoc/display-hidden-items.rs b/tests/rustdoc/display-hidden-items.rs
new file mode 100644
index 00000000000..d97d5b4a968
--- /dev/null
+++ b/tests/rustdoc/display-hidden-items.rs
@@ -0,0 +1,71 @@
+// Test to ensure that the `--document-hidden-items` option is working as expected.
+// compile-flags: -Z unstable-options --document-hidden-items
+// ignore-tidy-linelength
+
+#![crate_name = "foo"]
+
+// @has 'foo/index.html'
+// @has - '//*[@id="reexport.hidden_reexport"]/code' 'pub use hidden::inside_hidden as hidden_reexport;'
+#[doc(hidden)]
+pub use hidden::inside_hidden as hidden_reexport;
+
+// @has - '//*[@class="item-name"]/a[@class="trait"]' 'TraitHidden'
+// @has 'foo/trait.TraitHidden.html'
+#[doc(hidden)]
+pub trait TraitHidden {}
+
+// @has 'foo/index.html' '//*[@class="item-name"]/a[@class="trait"]' 'Trait'
+pub trait Trait {
+    // @has 'foo/trait.Trait.html'
+    // @has - '//*[@id="associatedconstant.BAR"]/*[@class="code-header"]' 'const BAR: u32 = 0u32'
+    #[doc(hidden)]
+    const BAR: u32 = 0;
+
+    // @has - '//*[@id="method.foo"]/*[@class="code-header"]' 'fn foo()'
+    #[doc(hidden)]
+    fn foo() {}
+}
+
+// @has 'foo/index.html' '//*[@class="item-name"]/a[@class="struct"]' 'Struct'
+// @has 'foo/struct.Struct.html'
+pub struct Struct {
+    // @has - '//*[@id="structfield.a"]/code' 'a: u32'
+    #[doc(hidden)]
+    pub a: u32,
+}
+
+impl Struct {
+    // @has - '//*[@id="method.new"]/*[@class="code-header"]' 'pub fn new() -> Self'
+    #[doc(hidden)]
+    pub fn new() -> Self { Self { a: 0 } }
+}
+
+impl Trait for Struct {
+    // @has - '//*[@id="associatedconstant.BAR"]/*[@class="code-header"]' 'const BAR: u32 = 0u32'
+    // @has - '//*[@id="method.foo"]/*[@class="code-header"]' 'fn foo()'
+}
+// @has - '//*[@id="impl-TraitHidden-for-Struct"]/*[@class="code-header"]' 'impl TraitHidden for Struct'
+impl TraitHidden for Struct {}
+
+// @has 'foo/index.html' '//*[@class="item-name"]/a[@class="enum"]' 'HiddenEnum'
+// @has 'foo/enum.HiddenEnum.html'
+#[doc(hidden)]
+pub enum HiddenEnum {
+    A,
+}
+
+// @has 'foo/index.html' '//*[@class="item-name"]/a[@class="enum"]' 'Enum'
+pub enum Enum {
+    // @has 'foo/enum.Enum.html' '//*[@id="variant.A"]/*[@class="code-header"]' 'A'
+    #[doc(hidden)]
+    A,
+}
+
+// @has 'foo/index.html' '//*[@class="item-name"]/a[@class="mod"]' 'hidden'
+#[doc(hidden)]
+pub mod hidden {
+    // @has 'foo/hidden/index.html'
+    // @has - '//*[@class="item-name"]/a[@class="fn"]' 'inside_hidden'
+    // @has 'foo/hidden/fn.inside_hidden.html'
+    pub fn inside_hidden() {}
+}
diff --git a/tests/rustdoc/issue-105735-overlapping-reexport-2.rs b/tests/rustdoc/issue-105735-overlapping-reexport-2.rs
new file mode 100644
index 00000000000..91082483948
--- /dev/null
+++ b/tests/rustdoc/issue-105735-overlapping-reexport-2.rs
@@ -0,0 +1,25 @@
+// Regression test to ensure that both `AtomicU8` items are displayed but not the re-export.
+
+#![crate_name = "foo"]
+#![no_std]
+
+// @has 'foo/index.html'
+// @has - '//*[@class="item-name"]/a[@class="type"]' 'AtomicU8'
+// @has - '//*[@class="item-name"]/a[@class="constant"]' 'AtomicU8'
+// We also ensure we don't have another item displayed.
+// @count - '//*[@id="main-content"]/*[@class="small-section-header"]' 2
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Type Definitions'
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Constants'
+
+mod other {
+    pub type AtomicU8 = ();
+}
+
+mod thing {
+    pub use crate::other::AtomicU8;
+
+    #[allow(non_upper_case_globals)]
+    pub const AtomicU8: () = ();
+}
+
+pub use crate::thing::AtomicU8;
diff --git a/tests/rustdoc/issue-105735-overlapping-reexport.rs b/tests/rustdoc/issue-105735-overlapping-reexport.rs
new file mode 100644
index 00000000000..50f2450b90a
--- /dev/null
+++ b/tests/rustdoc/issue-105735-overlapping-reexport.rs
@@ -0,0 +1,21 @@
+// Regression test to ensure that both `AtomicU8` items are displayed but not the re-export.
+
+#![crate_name = "foo"]
+#![no_std]
+
+// @has 'foo/index.html'
+// @has - '//*[@class="item-name"]/a[@class="struct"]' 'AtomicU8'
+// @has - '//*[@class="item-name"]/a[@class="constant"]' 'AtomicU8'
+// We also ensure we don't have another item displayed.
+// @count - '//*[@id="main-content"]/*[@class="small-section-header"]' 2
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Structs'
+// @has - '//*[@id="main-content"]/*[@class="small-section-header"]' 'Constants'
+
+mod thing {
+    pub use core::sync::atomic::AtomicU8;
+
+    #[allow(non_upper_case_globals)]
+    pub const AtomicU8: () = ();
+}
+
+pub use crate::thing::AtomicU8;
diff --git a/tests/ui/associated-consts/defaults-cyclic-fail.stderr b/tests/ui/associated-consts/defaults-cyclic-fail.stderr
index a1483911b29..ebdb76e4286 100644
--- a/tests/ui/associated-consts/defaults-cyclic-fail.stderr
+++ b/tests/ui/associated-consts/defaults-cyclic-fail.stderr
@@ -15,6 +15,7 @@ note: cycle used when const-evaluating + checking `main::promoted[1]`
    |
 LL |     assert_eq!(<() as Tr>::A, 0);
    |                ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
index be578176151..51bf0cb5e5c 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-impl.stderr
@@ -26,6 +26,7 @@ LL |     const BAR: u32 = IMPL_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-impl.rs:11:1: 11:19>::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
index 8347b260b56..8277d41a1c9 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait-default.stderr
@@ -26,6 +26,7 @@ LL |     const BAR: u32 = DEFAULT_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `FooDefault::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
index 3955a3120c4..9983ba794cd 100644
--- a/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
+++ b/tests/ui/associated-consts/issue-24949-assoc-const-static-recursion-trait.stderr
@@ -26,6 +26,7 @@ LL |     const BAR: u32 = TRAIT_REF_BAR;
    |     ^^^^^^^^^^^^^^
    = note: ...which again requires elaborating drops for `<impl at $DIR/issue-24949-assoc-const-static-recursion-trait.rs:11:1: 11:28>::BAR`, completing the cycle
    = note: cycle used when running analysis passes on this crate
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr b/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr
index 23269e1afab..3c373f139cb 100644
--- a/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr
+++ b/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-adt.stderr
@@ -37,6 +37,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr b/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr
index aaa9a39ea0f..ab6a97b3d85 100644
--- a/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr
+++ b/tests/ui/associated-inherent-types/bugs/cycle-iat-inside-of-where-predicate.stderr
@@ -31,6 +31,7 @@ LL | | // FIXME(inherent_associated_types): This shouldn't lead to a cycle error
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-type-bounds/ambiguous-associated-type2.rs b/tests/ui/associated-type-bounds/ambiguous-associated-type2.rs
index 48de593342f..e9cd57f1739 100644
--- a/tests/ui/associated-type-bounds/ambiguous-associated-type2.rs
+++ b/tests/ui/associated-type-bounds/ambiguous-associated-type2.rs
@@ -7,4 +7,6 @@ trait Bar<T> {
 trait Baz: Foo + Bar<Self::Item> {}
 //~^ ERROR cycle detected when computing the super traits of `Baz` with associated type name `Item` [E0391]
 
+
+
 fn main() {}
diff --git a/tests/ui/associated-type-bounds/ambiguous-associated-type2.stderr b/tests/ui/associated-type-bounds/ambiguous-associated-type2.stderr
index 575b00e09b0..f2604f0ba88 100644
--- a/tests/ui/associated-type-bounds/ambiguous-associated-type2.stderr
+++ b/tests/ui/associated-type-bounds/ambiguous-associated-type2.stderr
@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `Baz`
    |
 LL | trait Baz: Foo + Bar<Self::Item> {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/associated-types/issue-20825.stderr b/tests/ui/associated-types/issue-20825.stderr
index c4dea68b884..02b3536e2d1 100644
--- a/tests/ui/associated-types/issue-20825.stderr
+++ b/tests/ui/associated-types/issue-20825.stderr
@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `Processor`
    |
 LL | pub trait Processor: Subscriber<Input = Self::Input> {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/check-cfg/compact-values.stderr b/tests/ui/check-cfg/compact-values.stderr
index 70a967c0e5f..5f8dbbdb05c 100644
--- a/tests/ui/check-cfg/compact-values.stderr
+++ b/tests/ui/check-cfg/compact-values.stderr
@@ -4,7 +4,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(target(os = "linux", arch = "X"))]
    |                            ^^^^^^^^^^
    |
-   = note: expected values for `target_arch` are: `aarch64`, `arm`, `avr`, `bpf`, `hexagon`, `loongarch64`, `m68k`, `mips`, `mips64`, `msp430`, `nvptx64`, `powerpc`, `powerpc64`, `riscv32`, `riscv64`, `s390x`, `sparc`, `sparc64`, `wasm32`, `wasm64`, `x86`, `x86_64`
+   = note: expected values for `target_arch` are: `aarch64`, `arm`, `avr`, `bpf`, `hexagon`, `loongarch64`, `m68k`, `mips`, `mips32r6`, `mips64`, `mips64r6`, `msp430`, `nvptx64`, `powerpc`, `powerpc64`, `riscv32`, `riscv64`, `s390x`, `sparc`, `sparc64`, `wasm32`, `wasm64`, `x86`, `x86_64`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/coherence/coherence-inherited-assoc-ty-cycle-err.stderr b/tests/ui/coherence/coherence-inherited-assoc-ty-cycle-err.stderr
index 7bd50649d6d..684e528220f 100644
--- a/tests/ui/coherence/coherence-inherited-assoc-ty-cycle-err.stderr
+++ b/tests/ui/coherence/coherence-inherited-assoc-ty-cycle-err.stderr
@@ -20,6 +20,7 @@ note: cycle used when coherence checking all impls of trait `Trait`
    |
 LL | trait Trait<T> { type Assoc; }
    | ^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error; 1 warning emitted
 
diff --git a/tests/ui/const-generics/generic_const_exprs/closures.stderr b/tests/ui/const-generics/generic_const_exprs/closures.stderr
index a7d891d7790..45d7922bd0b 100644
--- a/tests/ui/const-generics/generic_const_exprs/closures.stderr
+++ b/tests/ui/const-generics/generic_const_exprs/closures.stderr
@@ -20,6 +20,7 @@ note: cycle used when checking that `test` is well-formed
    |
 LL | fn test<const N: usize>() -> [u8; N + (|| 42)()] {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/const-generics/issues/issue-83765.stderr b/tests/ui/const-generics/issues/issue-83765.stderr
index d7b2b006c2a..df734933c25 100644
--- a/tests/ui/const-generics/issues/issue-83765.stderr
+++ b/tests/ui/const-generics/issues/issue-83765.stderr
@@ -15,6 +15,7 @@ note: cycle used when computing candidate for `<LazyUpdim<'_, T, { T::DIM }, DIM
    |
 LL | trait TensorDimension {
    | ^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/const-size_of-cycle.stderr b/tests/ui/consts/const-size_of-cycle.stderr
index 17088d9995f..46b432357aa 100644
--- a/tests/ui/consts/const-size_of-cycle.stderr
+++ b/tests/ui/consts/const-size_of-cycle.stderr
@@ -23,6 +23,7 @@ note: cycle used when checking that `Foo` is well-formed
    |
 LL | struct Foo {
    | ^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/issue-103790.stderr b/tests/ui/consts/issue-103790.stderr
index 34d8ee281cf..67334469dcd 100644
--- a/tests/ui/consts/issue-103790.stderr
+++ b/tests/ui/consts/issue-103790.stderr
@@ -34,6 +34,7 @@ note: cycle used when computing type of `S`
    |
 LL | struct S<const S: (), const S: S = { S }>;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `S`
   --> $DIR/issue-103790.rs:4:1
@@ -58,6 +59,7 @@ LL | | struct S<const S: (), const S: S = { S }>;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 4 previous errors
 
diff --git a/tests/ui/consts/issue-36163.stderr b/tests/ui/consts/issue-36163.stderr
index 7137c053847..190b41062f8 100644
--- a/tests/ui/consts/issue-36163.stderr
+++ b/tests/ui/consts/issue-36163.stderr
@@ -15,6 +15,7 @@ note: cycle used when simplifying constant for the type system `Foo::B::{constan
    |
 LL |     B = A,
    |         ^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/issue-44415.stderr b/tests/ui/consts/issue-44415.stderr
index ec64b956dfe..01d24a62081 100644
--- a/tests/ui/consts/issue-44415.stderr
+++ b/tests/ui/consts/issue-44415.stderr
@@ -23,6 +23,7 @@ note: cycle used when checking that `Foo` is well-formed
    |
 LL | struct Foo {
    | ^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/recursive-zst-static.default.stderr b/tests/ui/consts/recursive-zst-static.default.stderr
index d68960b0972..d592b5aeef5 100644
--- a/tests/ui/consts/recursive-zst-static.default.stderr
+++ b/tests/ui/consts/recursive-zst-static.default.stderr
@@ -19,6 +19,7 @@ LL | | fn main() {
 LL | |     FOO
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/recursive-zst-static.unleash.stderr b/tests/ui/consts/recursive-zst-static.unleash.stderr
index d68960b0972..d592b5aeef5 100644
--- a/tests/ui/consts/recursive-zst-static.unleash.stderr
+++ b/tests/ui/consts/recursive-zst-static.unleash.stderr
@@ -19,6 +19,7 @@ LL | | fn main() {
 LL | |     FOO
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/consts/write-to-static-mut-in-static.stderr b/tests/ui/consts/write-to-static-mut-in-static.stderr
index 395b2d42f97..5665e56439e 100644
--- a/tests/ui/consts/write-to-static-mut-in-static.stderr
+++ b/tests/ui/consts/write-to-static-mut-in-static.stderr
@@ -27,6 +27,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/cycle-trait/cycle-trait-default-type-trait.stderr b/tests/ui/cycle-trait/cycle-trait-default-type-trait.stderr
index 9d715f49471..3b66704d613 100644
--- a/tests/ui/cycle-trait/cycle-trait-default-type-trait.stderr
+++ b/tests/ui/cycle-trait/cycle-trait-default-type-trait.stderr
@@ -14,6 +14,7 @@ LL | | }
 LL | |
 LL | | fn main() { }
    | |_____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/cycle-trait/cycle-trait-supertrait-direct.stderr b/tests/ui/cycle-trait/cycle-trait-supertrait-direct.stderr
index e2b2aac05ac..03cb5015ab0 100644
--- a/tests/ui/cycle-trait/cycle-trait-supertrait-direct.stderr
+++ b/tests/ui/cycle-trait/cycle-trait-supertrait-direct.stderr
@@ -12,6 +12,7 @@ LL | / trait Chromosome: Chromosome {
 LL | |
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr b/tests/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr
index c903e114657..c7cc3143520 100644
--- a/tests/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr
+++ b/tests/ui/cycle-trait/cycle-trait-supertrait-indirect.stderr
@@ -15,6 +15,7 @@ note: cycle used when computing the super predicates of `A`
    |
 LL | trait A: B {
    |          ^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/cycle-trait/issue-12511.stderr b/tests/ui/cycle-trait/issue-12511.stderr
index 558aad10946..f5e4f83473d 100644
--- a/tests/ui/cycle-trait/issue-12511.stderr
+++ b/tests/ui/cycle-trait/issue-12511.stderr
@@ -17,6 +17,7 @@ LL | / trait T1 : T2 {
 LL | |
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/dyn-star/param-env-region-infer.next.stderr b/tests/ui/dyn-star/param-env-region-infer.next.stderr
index dd724a65908..28aec533a00 100644
--- a/tests/ui/dyn-star/param-env-region-infer.next.stderr
+++ b/tests/ui/dyn-star/param-env-region-infer.next.stderr
@@ -23,6 +23,7 @@ LL | | use std::fmt::Debug;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/fmt/closing-brace-as-fill.rs b/tests/ui/fmt/closing-brace-as-fill.rs
new file mode 100644
index 00000000000..6ad257f943e
--- /dev/null
+++ b/tests/ui/fmt/closing-brace-as-fill.rs
@@ -0,0 +1,8 @@
+// issue: 112732
+
+// `}` is typoed since it is interpreted as a fill character rather than a closing bracket
+
+fn main() {
+    println!("Hello, world! {0:}<3", 2);
+    //~^ ERROR invalid format string: expected `'}'` but string was terminated
+}
diff --git a/tests/ui/fmt/closing-brace-as-fill.stderr b/tests/ui/fmt/closing-brace-as-fill.stderr
new file mode 100644
index 00000000000..aa1e5aff652
--- /dev/null
+++ b/tests/ui/fmt/closing-brace-as-fill.stderr
@@ -0,0 +1,12 @@
+error: invalid format string: expected `'}'` but string was terminated
+  --> $DIR/closing-brace-as-fill.rs:6:35
+   |
+LL |     println!("Hello, world! {0:}<3", 2);
+   |                                -  ^ expected `'}'` in format string
+   |                                |
+   |                                this is not interpreted as a formatting closing brace
+   |
+   = note: the character `'}'` is interpreted as a fill character because of the `:` that precedes it
+
+error: aborting due to previous error
+
diff --git a/tests/ui/fmt/format-string-error-2.stderr b/tests/ui/fmt/format-string-error-2.stderr
index 76cdfbb93bf..dfd24bf60ad 100644
--- a/tests/ui/fmt/format-string-error-2.stderr
+++ b/tests/ui/fmt/format-string-error-2.stderr
@@ -10,7 +10,7 @@ error: invalid format string: expected `'}'`, found `'a'`
 LL |     format!("{
    |              - because of this opening brace
 LL |     a");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -21,7 +21,7 @@ LL |     format!("{ \
    |              - because of this opening brace
 LL |                \
 LL |     b");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -29,7 +29,7 @@ error: invalid format string: expected `'}'`, found `'\'`
   --> $DIR/format-string-error-2.rs:11:18
    |
 LL |     format!(r#"{ \
-   |                - ^ expected `}` in format string
+   |                - ^ expected `'}'` in format string
    |                |
    |                because of this opening brace
    |
@@ -39,7 +39,7 @@ error: invalid format string: expected `'}'`, found `'\'`
   --> $DIR/format-string-error-2.rs:15:18
    |
 LL |     format!(r#"{ \n
-   |                - ^ expected `}` in format string
+   |                - ^ expected `'}'` in format string
    |                |
    |                because of this opening brace
    |
@@ -52,7 +52,7 @@ LL |     format!("{ \n
    |              - because of this opening brace
 LL | \n
 LL |     e");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -62,7 +62,7 @@ error: invalid format string: expected `'}'`, found `'a'`
 LL |     {
    |     - because of this opening brace
 LL |     a");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -72,7 +72,7 @@ error: invalid format string: expected `'}'`, found `'a'`
 LL |     {
    |     - because of this opening brace
 LL |     a
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -83,7 +83,7 @@ LL |     { \
    |     - because of this opening brace
 LL |         \
 LL |     b");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -94,7 +94,7 @@ LL |     { \
    |     - because of this opening brace
 LL |         \
 LL |     b \
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -102,7 +102,7 @@ error: invalid format string: expected `'}'`, found `'\'`
   --> $DIR/format-string-error-2.rs:45:8
    |
 LL | raw  { \
-   |      - ^ expected `}` in format string
+   |      - ^ expected `'}'` in format string
    |      |
    |      because of this opening brace
    |
@@ -112,7 +112,7 @@ error: invalid format string: expected `'}'`, found `'\'`
   --> $DIR/format-string-error-2.rs:50:8
    |
 LL | raw  { \n
-   |      - ^ expected `}` in format string
+   |      - ^ expected `'}'` in format string
    |      |
    |      because of this opening brace
    |
@@ -125,7 +125,7 @@ LL |   { \n
    |   - because of this opening brace
 LL | \n
 LL |     e");
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
@@ -135,7 +135,7 @@ error: invalid format string: expected `'}'`, found `'a'`
 LL |     {
    |     - because of this opening brace
 LL |     asdf}
-   |     ^ expected `}` in format string
+   |     ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
diff --git a/tests/ui/fmt/format-string-error.stderr b/tests/ui/fmt/format-string-error.stderr
index 8a32c225485..37a181e6fcb 100644
--- a/tests/ui/fmt/format-string-error.stderr
+++ b/tests/ui/fmt/format-string-error.stderr
@@ -62,7 +62,7 @@ error: invalid format string: expected `'}'`, found `'\'`
   --> $DIR/format-string-error.rs:19:23
    |
 LL |     let _ = format!("{\}");
-   |                      -^ expected `}` in format string
+   |                      -^ expected `'}'` in format string
    |                      |
    |                      because of this opening brace
    |
diff --git a/tests/ui/fmt/format-string-wrong-order.stderr b/tests/ui/fmt/format-string-wrong-order.stderr
index 461af354a4e..0a2e04026d9 100644
--- a/tests/ui/fmt/format-string-wrong-order.stderr
+++ b/tests/ui/fmt/format-string-wrong-order.stderr
@@ -26,7 +26,7 @@ error: invalid format string: expected `'}'`, found `'?'`
   --> $DIR/format-string-wrong-order.rs:9:15
    |
 LL |     format!("{??}", bar);
-   |              -^ expected `}` in format string
+   |              -^ expected `'}'` in format string
    |              |
    |              because of this opening brace
    |
@@ -36,7 +36,7 @@ error: invalid format string: expected `'}'`, found `'?'`
   --> $DIR/format-string-wrong-order.rs:11:15
    |
 LL |     format!("{?;bar}");
-   |              -^ expected `}` in format string
+   |              -^ expected `'}'` in format string
    |              |
    |              because of this opening brace
    |
diff --git a/tests/ui/fmt/ifmt-bad-arg.stderr b/tests/ui/fmt/ifmt-bad-arg.stderr
index ed008c454a3..09ce3dca411 100644
--- a/tests/ui/fmt/ifmt-bad-arg.stderr
+++ b/tests/ui/fmt/ifmt-bad-arg.stderr
@@ -178,7 +178,7 @@ error: invalid format string: expected `'}'`, found `'t'`
 LL | ninth number: {
    |               - because of this opening brace
 LL | tenth number: {}",
-   | ^ expected `}` in format string
+   | ^ expected `'}'` in format string
    |
    = note: if you intended to print `{`, you can escape it using `{{`
 
diff --git a/tests/ui/impl-trait/auto-trait-leak.stderr b/tests/ui/impl-trait/auto-trait-leak.stderr
index 92a9763bc9b..a024cff0b8d 100644
--- a/tests/ui/impl-trait/auto-trait-leak.stderr
+++ b/tests/ui/impl-trait/auto-trait-leak.stderr
@@ -33,6 +33,7 @@ LL | | fn send<T: Send>(_: T) {}
 LL | |     Rc::new(String::from("foo"))
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `cycle1::{opaque#0}`
   --> $DIR/auto-trait-leak.rs:11:16
@@ -68,6 +69,7 @@ LL | | fn send<T: Send>(_: T) {}
 LL | |     Rc::new(String::from("foo"))
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of opaque type satisfies auto traits
   --> $DIR/auto-trait-leak.rs:21:10
diff --git a/tests/ui/impl-trait/defined-by-trait-resolution.rs b/tests/ui/impl-trait/defined-by-trait-resolution.rs
new file mode 100644
index 00000000000..1744046ddbb
--- /dev/null
+++ b/tests/ui/impl-trait/defined-by-trait-resolution.rs
@@ -0,0 +1,12 @@
+//! The trait query `foo: Fn() -> u8` is a valid defining use of RPIT.
+
+// build-pass
+
+fn returns_u8(_: impl Fn() -> u8) {}
+
+pub fn foo() -> impl Sized {
+    returns_u8(foo);
+    0u8
+}
+
+fn main() {}
diff --git a/tests/ui/infinite/infinite-trait-alias-recursion.stderr b/tests/ui/infinite/infinite-trait-alias-recursion.stderr
index 683987b4943..39d7aa4c16a 100644
--- a/tests/ui/infinite/infinite-trait-alias-recursion.stderr
+++ b/tests/ui/infinite/infinite-trait-alias-recursion.stderr
@@ -21,6 +21,7 @@ note: cycle used when collecting item types in top-level module
    |
 LL | trait T1 = T2;
    | ^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/infinite/infinite-type-alias-mutual-recursion.stderr b/tests/ui/infinite/infinite-type-alias-mutual-recursion.stderr
index 7f82b294434..bbdb1f70b80 100644
--- a/tests/ui/infinite/infinite-type-alias-mutual-recursion.stderr
+++ b/tests/ui/infinite/infinite-type-alias-mutual-recursion.stderr
@@ -28,6 +28,7 @@ LL | | type X3 = X1;
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/infinite/infinite-vec-type-recursion.stderr b/tests/ui/infinite/infinite-vec-type-recursion.stderr
index 1e487a5b11c..a21b033a9a9 100644
--- a/tests/ui/infinite/infinite-vec-type-recursion.stderr
+++ b/tests/ui/infinite/infinite-vec-type-recursion.stderr
@@ -16,6 +16,7 @@ LL | |
 LL | |
 LL | | fn main() { let b: X = Vec::new(); }
    | |____________________________________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/inline-const/interpolated.rs b/tests/ui/inline-const/interpolated.rs
new file mode 100644
index 00000000000..3fcc621c946
--- /dev/null
+++ b/tests/ui/inline-const/interpolated.rs
@@ -0,0 +1,32 @@
+// check-pass
+
+#![feature(inline_const)]
+
+// This used to be unsupported since the parser first tries to check if we have
+// any nested items, and then checks for statements (and expressions). The heuristic
+// that we were using to detect the beginning of a const item was incorrect, so
+// this used to fail.
+macro_rules! m {
+    ($b:block) => {
+        fn foo() {
+            const $b
+        }
+    }
+}
+
+// This has worked since inline-consts were implemented, since the position that
+// the const block is located at doesn't support nested items (e.g. because
+// `let x = const X: u32 = 1;` is invalid), so there's no ambiguity parsing the
+// inline const.
+macro_rules! m2 {
+    ($b:block) => {
+        fn foo2() {
+            let _ = const $b;
+        }
+    }
+}
+
+m!({});
+m2!({});
+
+fn main() {}
diff --git a/tests/ui/issues/issue-17252.stderr b/tests/ui/issues/issue-17252.stderr
index aca5242b296..daaf82e80ad 100644
--- a/tests/ui/issues/issue-17252.stderr
+++ b/tests/ui/issues/issue-17252.stderr
@@ -10,6 +10,7 @@ note: cycle used when const-evaluating + checking `main::{constant#0}`
    |
 LL |     let _x: [u8; FOO]; // caused stack overflow prior to fix
    |                  ^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-20772.stderr b/tests/ui/issues/issue-20772.stderr
index 416fd8c062f..0c7e728c67e 100644
--- a/tests/ui/issues/issue-20772.stderr
+++ b/tests/ui/issues/issue-20772.stderr
@@ -10,6 +10,7 @@ note: cycle used when computing the super predicates of `T`
    |
 LL | trait T : Iterator<Item=Self::Item>
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-21177.stderr b/tests/ui/issues/issue-21177.stderr
index 6877a184605..8b749edcc77 100644
--- a/tests/ui/issues/issue-21177.stderr
+++ b/tests/ui/issues/issue-21177.stderr
@@ -10,6 +10,7 @@ note: cycle used when computing explicit predicates of `foo`
    |
 LL | fn foo<T: Trait<A = T::B>>() { }
    |                     ^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-23302-1.stderr b/tests/ui/issues/issue-23302-1.stderr
index 9366050d7ec..d807e24403e 100644
--- a/tests/ui/issues/issue-23302-1.stderr
+++ b/tests/ui/issues/issue-23302-1.stderr
@@ -10,6 +10,7 @@ note: cycle used when simplifying constant for the type system `X::A::{constant#
    |
 LL |     A = X::A as isize,
    |         ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-23302-2.stderr b/tests/ui/issues/issue-23302-2.stderr
index b97ae287a47..91b39dba1ba 100644
--- a/tests/ui/issues/issue-23302-2.stderr
+++ b/tests/ui/issues/issue-23302-2.stderr
@@ -10,6 +10,7 @@ note: cycle used when simplifying constant for the type system `Y::A::{constant#
    |
 LL |     A = Y::B as isize,
    |         ^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-23302-3.stderr b/tests/ui/issues/issue-23302-3.stderr
index c6cafe575e5..6b708d81f73 100644
--- a/tests/ui/issues/issue-23302-3.stderr
+++ b/tests/ui/issues/issue-23302-3.stderr
@@ -15,6 +15,7 @@ note: cycle used when simplifying constant for the type system `A`
    |
 LL | const A: i32 = B;
    | ^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/issues/issue-34373.stderr b/tests/ui/issues/issue-34373.stderr
index 8be3cfa72fb..0f0821518a4 100644
--- a/tests/ui/issues/issue-34373.stderr
+++ b/tests/ui/issues/issue-34373.stderr
@@ -21,6 +21,7 @@ LL | |     fn foo(_: T) {}
 LL | | fn main() {
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/lint/lint-qualification.fixed b/tests/ui/lint/lint-qualification.fixed
new file mode 100644
index 00000000000..c1449301362
--- /dev/null
+++ b/tests/ui/lint/lint-qualification.fixed
@@ -0,0 +1,21 @@
+// run-rustfix
+#![deny(unused_qualifications)]
+#![allow(deprecated)]
+
+mod foo {
+    pub fn bar() {}
+}
+
+fn main() {
+    use foo::bar;
+    bar(); //~ ERROR: unnecessary qualification
+    bar();
+
+    let _ = || -> Result<(), ()> { try!(Ok(())); Ok(()) }; // issue #37345
+
+    macro_rules! m { () => {
+        $crate::foo::bar(); // issue #37357
+        ::foo::bar(); // issue #38682
+    } }
+    m!();
+}
diff --git a/tests/ui/lint/lint-qualification.rs b/tests/ui/lint/lint-qualification.rs
index 0cace0ca035..80904303559 100644
--- a/tests/ui/lint/lint-qualification.rs
+++ b/tests/ui/lint/lint-qualification.rs
@@ -1,3 +1,4 @@
+// run-rustfix
 #![deny(unused_qualifications)]
 #![allow(deprecated)]
 
diff --git a/tests/ui/lint/lint-qualification.stderr b/tests/ui/lint/lint-qualification.stderr
index d09cb78c4f0..90a06bc6cbe 100644
--- a/tests/ui/lint/lint-qualification.stderr
+++ b/tests/ui/lint/lint-qualification.stderr
@@ -1,18 +1,19 @@
 error: unnecessary qualification
-  --> $DIR/lint-qualification.rs:10:5
+  --> $DIR/lint-qualification.rs:11:5
    |
 LL |     foo::bar();
    |     ^^^^^^^^
    |
 note: the lint level is defined here
-  --> $DIR/lint-qualification.rs:1:9
+  --> $DIR/lint-qualification.rs:2:9
    |
 LL | #![deny(unused_qualifications)]
    |         ^^^^^^^^^^^^^^^^^^^^^
-help: replace it with the unqualified path
+help: remove the unnecessary path segments
+   |
+LL -     foo::bar();
+LL +     bar();
    |
-LL |     bar();
-   |     ~~~
 
 error: aborting due to previous error
 
diff --git a/tests/ui/modules/issue-107649.stderr b/tests/ui/modules/issue-107649.stderr
index 38a910b57b4..5705e84e0d9 100644
--- a/tests/ui/modules/issue-107649.stderr
+++ b/tests/ui/modules/issue-107649.stderr
@@ -11,7 +11,7 @@ help: consider annotating `Dummy` with `#[derive(Debug)]`
    --> $DIR/auxiliary/dummy_lib.rs:2:1
     |
 2   + #[derive(Debug)]
-3   | #[path = "auxiliary/dummy_lib.rs"]
+3   | pub struct Dummy;
     |
 
 error: aborting due to previous error
diff --git a/tests/ui/recursion/issue-26548-recursion-via-normalize.rs b/tests/ui/recursion/issue-26548-recursion-via-normalize.rs
index 91958dffcf4..6c7fc4beb54 100644
--- a/tests/ui/recursion/issue-26548-recursion-via-normalize.rs
+++ b/tests/ui/recursion/issue-26548-recursion-via-normalize.rs
@@ -1,4 +1,5 @@
 //~ ERROR cycle detected when computing layout of `core::option::Option<S>`
+//~| NOTE see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 //~| NOTE ...which requires computing layout of `S`...
 //~| NOTE ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
 //~| NOTE ...which again requires computing layout of `core::option::Option<S>`, completing the cycle
diff --git a/tests/ui/recursion/issue-26548-recursion-via-normalize.stderr b/tests/ui/recursion/issue-26548-recursion-via-normalize.stderr
index a75097cdbfb..514bed60700 100644
--- a/tests/ui/recursion/issue-26548-recursion-via-normalize.stderr
+++ b/tests/ui/recursion/issue-26548-recursion-via-normalize.stderr
@@ -4,6 +4,7 @@ error[E0391]: cycle detected when computing layout of `core::option::Option<S>`
    = note: ...which requires computing layout of `core::option::Option<<S as Mirror>::It>`...
    = note: ...which again requires computing layout of `core::option::Option<S>`, completing the cycle
    = note: cycle used when computing layout of `core::option::Option<<S as Mirror>::It>`
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/recursion/recursive-static-definition.stderr b/tests/ui/recursion/recursive-static-definition.stderr
index 1359761457a..b112228d403 100644
--- a/tests/ui/recursion/recursive-static-definition.stderr
+++ b/tests/ui/recursion/recursive-static-definition.stderr
@@ -18,6 +18,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.fixed b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.fixed
new file mode 100644
index 00000000000..e730f94660b
--- /dev/null
+++ b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.fixed
@@ -0,0 +1,31 @@
+// run-rustfix
+
+#![deny(unused_qualifications)]
+#![feature(unsized_fn_params)]
+
+#[allow(unused_imports)]
+use std::ops;
+use std::ops::Index;
+
+pub struct A;
+
+impl Index<str> for A {
+    //~^ ERROR unnecessary qualification
+    type Output = ();
+    fn index(&self, _: str) -> &Self::Output {
+        &()
+    }
+}
+
+mod inner {
+    pub trait Trait<T> {}
+}
+
+// the import needs to be here for the lint to show up
+#[allow(unused_imports)]
+use inner::Trait;
+
+impl Trait<u8> for () {}
+//~^ ERROR unnecessary qualification
+
+fn main() {}
diff --git a/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.rs b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.rs
new file mode 100644
index 00000000000..641c892e3de
--- /dev/null
+++ b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.rs
@@ -0,0 +1,31 @@
+// run-rustfix
+
+#![deny(unused_qualifications)]
+#![feature(unsized_fn_params)]
+
+#[allow(unused_imports)]
+use std::ops;
+use std::ops::Index;
+
+pub struct A;
+
+impl ops::Index<str> for A {
+    //~^ ERROR unnecessary qualification
+    type Output = ();
+    fn index(&self, _: str) -> &Self::Output {
+        &()
+    }
+}
+
+mod inner {
+    pub trait Trait<T> {}
+}
+
+// the import needs to be here for the lint to show up
+#[allow(unused_imports)]
+use inner::Trait;
+
+impl inner::Trait<u8> for () {}
+//~^ ERROR unnecessary qualification
+
+fn main() {}
diff --git a/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.stderr b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.stderr
new file mode 100644
index 00000000000..d9c7fd21871
--- /dev/null
+++ b/tests/ui/resolve/issue-113808-invalid-unused-qualifications-suggestion.stderr
@@ -0,0 +1,31 @@
+error: unnecessary qualification
+  --> $DIR/issue-113808-invalid-unused-qualifications-suggestion.rs:12:6
+   |
+LL | impl ops::Index<str> for A {
+   |      ^^^^^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/issue-113808-invalid-unused-qualifications-suggestion.rs:3:9
+   |
+LL | #![deny(unused_qualifications)]
+   |         ^^^^^^^^^^^^^^^^^^^^^
+help: remove the unnecessary path segments
+   |
+LL - impl ops::Index<str> for A {
+LL + impl Index<str> for A {
+   |
+
+error: unnecessary qualification
+  --> $DIR/issue-113808-invalid-unused-qualifications-suggestion.rs:28:6
+   |
+LL | impl inner::Trait<u8> for () {}
+   |      ^^^^^^^^^^^^^^^^
+   |
+help: remove the unnecessary path segments
+   |
+LL - impl inner::Trait<u8> for () {}
+LL + impl Trait<u8> for () {}
+   |
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui/resolve/resolve-self-in-impl.stderr b/tests/ui/resolve/resolve-self-in-impl.stderr
index 9f9ed68898f..183a17171f7 100644
--- a/tests/ui/resolve/resolve-self-in-impl.stderr
+++ b/tests/ui/resolve/resolve-self-in-impl.stderr
@@ -56,6 +56,7 @@ LL | | trait Tr<T = u8> {
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 6 previous errors
 
diff --git a/tests/ui/resolve/unused-qualifications-suggestion.stderr b/tests/ui/resolve/unused-qualifications-suggestion.stderr
index c8e91e07295..e3dac37fc6e 100644
--- a/tests/ui/resolve/unused-qualifications-suggestion.stderr
+++ b/tests/ui/resolve/unused-qualifications-suggestion.stderr
@@ -9,10 +9,11 @@ note: the lint level is defined here
    |
 LL | #![deny(unused_qualifications)]
    |         ^^^^^^^^^^^^^^^^^^^^^
-help: replace it with the unqualified path
+help: remove the unnecessary path segments
+   |
+LL -     foo::bar();
+LL +     bar();
    |
-LL |     bar();
-   |     ~~~
 
 error: unnecessary qualification
   --> $DIR/unused-qualifications-suggestion.rs:21:5
@@ -20,10 +21,11 @@ error: unnecessary qualification
 LL |     baz::qux::quux();
    |     ^^^^^^^^^^^^^^
    |
-help: replace it with the unqualified path
+help: remove the unnecessary path segments
+   |
+LL -     baz::qux::quux();
+LL +     quux();
    |
-LL |     quux();
-   |     ~~~~
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.rs b/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.rs
index d7a418959bf..880907b24b4 100644
--- a/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.rs
+++ b/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.rs
@@ -6,6 +6,10 @@
 // compile-flags: --crate-type lib --emit link
 // normalize-stderr-test: "[^ ']*/dlltool.exe" -> "$$DLLTOOL"
 // normalize-stderr-test: "[^ ]*/foo.def" -> "$$DEF_FILE"
+// normalize-stderr-test: "[^ ]*/foo.lib" -> "$$LIB_FILE"
+// normalize-stderr-test: "-m [^ ]*" -> "$$TARGET_MACHINE"
+// normalize-stderr-test: "-f [^ ]*" -> "$$ASM_FLAGS"
+// normalize-stderr-test: "--temp-prefix [^ ]*/foo.dll" -> "$$TEMP_PREFIX"
 #[link(name = "foo", kind = "raw-dylib")]
 extern "C" {
     // `@1` is an invalid name to export, as it usually indicates that something
diff --git a/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.stderr b/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.stderr
index 020ac6a2b67..cc532ccc451 100644
--- a/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.stderr
+++ b/tests/ui/rfcs/rfc-2627-raw-dylib/dlltool-failed.stderr
@@ -1,4 +1,5 @@
-error: Dlltool could not create import library: 
+error: Dlltool could not create import library with $DLLTOOL -d $DEF_FILE -D foo.dll -l $LIB_FILE $TARGET_MACHINE $ASM_FLAGS --no-leading-underscore $TEMP_PREFIX:
+       
        $DLLTOOL: Syntax error in def file $DEF_FILE:1
 
 error: aborting due to previous error
diff --git a/tests/ui/rfcs/rfc-2627-raw-dylib/multiple-declarations.stderr b/tests/ui/rfcs/rfc-2627-raw-dylib/multiple-declarations.stderr
index 51010840548..dfd24566953 100644
--- a/tests/ui/rfcs/rfc-2627-raw-dylib/multiple-declarations.stderr
+++ b/tests/ui/rfcs/rfc-2627-raw-dylib/multiple-declarations.stderr
@@ -2,7 +2,7 @@ error: multiple declarations of external function `f` from library `foo.dll` hav
   --> $DIR/multiple-declarations.rs:13:9
    |
 LL |         fn f(x: i32);
-   |         ^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/tests/ui/rfcs/rfc-2627-raw-dylib/unsupported-abi.stderr b/tests/ui/rfcs/rfc-2627-raw-dylib/unsupported-abi.stderr
index f8265ae6919..f69275a0125 100644
--- a/tests/ui/rfcs/rfc-2627-raw-dylib/unsupported-abi.stderr
+++ b/tests/ui/rfcs/rfc-2627-raw-dylib/unsupported-abi.stderr
@@ -2,7 +2,7 @@ error: ABI not supported by `#[link(kind = "raw-dylib")]` on this architecture
   --> $DIR/unsupported-abi.rs:6:5
    |
 LL |     fn f(x: i32);
-   |     ^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^
 
 error: aborting due to previous error
 
diff --git a/tests/ui/simd/intrinsic/float-minmax-pass.rs b/tests/ui/simd/intrinsic/float-minmax-pass.rs
index d79be61f909..968b074b6ef 100644
--- a/tests/ui/simd/intrinsic/float-minmax-pass.rs
+++ b/tests/ui/simd/intrinsic/float-minmax-pass.rs
@@ -21,7 +21,7 @@ fn main() {
 
     #[cfg(not(any(target_arch = "mips", target_arch = "mips64")))]
     let nan = f32::NAN;
-    // MIPS hardware treats f32::NAN as SNAN. Clear the signaling bit.
+    // MIPS hardware except MIPS R6 treats f32::NAN as SNAN. Clear the signaling bit.
     // See https://github.com/rust-lang/rust/issues/52746.
     #[cfg(any(target_arch = "mips", target_arch = "mips64"))]
     let nan = f32::from_bits(f32::NAN.to_bits() - 1);
diff --git a/tests/ui/sized/recursive-type-2.stderr b/tests/ui/sized/recursive-type-2.stderr
index d0e6e9db07e..0f72f74145e 100644
--- a/tests/ui/sized/recursive-type-2.stderr
+++ b/tests/ui/sized/recursive-type-2.stderr
@@ -7,6 +7,7 @@ note: cycle used when elaborating drops for `main`
    |
 LL | fn main() {
    | ^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/traits/new-solver/alias-bound-preference.rs b/tests/ui/traits/new-solver/alias-bound-preference.rs
new file mode 100644
index 00000000000..e4e0f634ef7
--- /dev/null
+++ b/tests/ui/traits/new-solver/alias-bound-preference.rs
@@ -0,0 +1,39 @@
+// revisions: old next
+//[next] compile-flags: -Ztrait-solver=next
+// run-pass
+
+// A test for https://github.com/rust-lang/trait-system-refactor-initiative/issues/45.
+
+trait Trait {
+    type Assoc: Into<u32>;
+}
+impl<T: Into<u32>> Trait for T {
+    type Assoc = T;
+}
+fn prefer_alias_bound_projection<T: Trait>(x: T::Assoc) {
+    // There are two possible types for `x`:
+    // - `u32` by using the "alias bound" of `<T as Trait>::Assoc`
+    // - `<T as Trait>::Assoc`, i.e. `u16`, by using `impl<T> From<T> for T`
+    //
+    // We infer the type of `x` to be `u32` here as it is highly likely
+    // that this is expected by the user.
+    let x = x.into();
+    assert_eq!(std::mem::size_of_val(&x), 4);
+}
+
+fn impl_trait() -> impl Into<u32> {
+    0u16
+}
+
+fn main() {
+    // There are two possible types for `x`:
+    // - `u32` by using the "alias bound" of `impl Into<u32>`
+    // - `impl Into<u32>`, i.e. `u16`, by using `impl<T> From<T> for T`
+    //
+    // We infer the type of `x` to be `u32` here as it is highly likely
+    // that this is expected by the user.
+    let x = impl_trait().into();
+    assert_eq!(std::mem::size_of_val(&x), 4);
+
+    prefer_alias_bound_projection::<u16>(1);
+}
diff --git a/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr b/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
index ca98e183150..62c732fb1d9 100644
--- a/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
+++ b/tests/ui/traits/trait-upcasting/cyclic-trait-resolution.stderr
@@ -10,6 +10,7 @@ note: cycle used when collecting item types in top-level module
    |
 LL | trait A: B + A {}
    | ^^^^^^^^^^^^^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/transmutability/issue-110892.rs b/tests/ui/transmutability/issue-110892.rs
new file mode 100644
index 00000000000..ce926b39996
--- /dev/null
+++ b/tests/ui/transmutability/issue-110892.rs
@@ -0,0 +1,40 @@
+// check-fail
+#![feature(generic_const_exprs, transmutability)]
+#![allow(incomplete_features)]
+
+mod assert {
+    use std::mem::{Assume, BikeshedIntrinsicFrom};
+
+    pub fn is_transmutable<
+        Src,
+        Dst,
+        Context,
+        const ASSUME_ALIGNMENT: bool,
+        const ASSUME_LIFETIMES: bool,
+        const ASSUME_SAFETY: bool,
+        const ASSUME_VALIDITY: bool,
+    >()
+    where
+        Dst: BikeshedIntrinsicFrom<
+            Src,
+            Context,
+            { from_options(ASSUME_ALIGNMENT, ASSUME_LIFETIMES, ASSUME_SAFETY, ASSUME_VALIDITY) }
+        >,
+    {}
+
+    // This should not cause an ICE
+    const fn from_options(
+        , //~ ERROR expected parameter name, found `,`
+        , //~ ERROR expected parameter name, found `,`
+        , //~ ERROR expected parameter name, found `,`
+        , //~ ERROR expected parameter name, found `,`
+    ) -> Assume {} //~ ERROR mismatched types
+}
+
+fn main() {
+    struct Context;
+    #[repr(C)] struct Src;
+    #[repr(C)] struct Dst;
+
+    assert::is_transmutable::<Src, Dst, Context, false, false, { true }, false>();
+}
diff --git a/tests/ui/transmutability/issue-110892.stderr b/tests/ui/transmutability/issue-110892.stderr
new file mode 100644
index 00000000000..13654307aee
--- /dev/null
+++ b/tests/ui/transmutability/issue-110892.stderr
@@ -0,0 +1,36 @@
+error: expected parameter name, found `,`
+  --> $DIR/issue-110892.rs:27:9
+   |
+LL |         ,
+   |         ^ expected parameter name
+
+error: expected parameter name, found `,`
+  --> $DIR/issue-110892.rs:28:9
+   |
+LL |         ,
+   |         ^ expected parameter name
+
+error: expected parameter name, found `,`
+  --> $DIR/issue-110892.rs:29:9
+   |
+LL |         ,
+   |         ^ expected parameter name
+
+error: expected parameter name, found `,`
+  --> $DIR/issue-110892.rs:30:9
+   |
+LL |         ,
+   |         ^ expected parameter name
+
+error[E0308]: mismatched types
+  --> $DIR/issue-110892.rs:31:10
+   |
+LL |     const fn from_options(
+   |              ------------ implicitly returns `()` as its body has no tail or `return` expression
+...
+LL |     ) -> Assume {}
+   |          ^^^^^^ expected `Assume`, found `()`
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/type-alias-enum-variants/self-in-enum-definition.stderr b/tests/ui/type-alias-enum-variants/self-in-enum-definition.stderr
index c943a4918ba..aa79b1a57c4 100644
--- a/tests/ui/type-alias-enum-variants/self-in-enum-definition.stderr
+++ b/tests/ui/type-alias-enum-variants/self-in-enum-definition.stderr
@@ -67,6 +67,7 @@ LL | |     V2 = Self::V1 as u8 + 1,    // OK; See #50072.
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to previous error
 
diff --git a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
index dd56c59bf5f..5bd0f76c31f 100644
--- a/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
+++ b/tests/ui/type-alias-impl-trait/auto-trait-leakage3.stderr
@@ -16,6 +16,7 @@ note: cycle used when checking item types in module `m`
    |
 LL | mod m {
    | ^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
   --> $DIR/auto-trait-leakage3.rs:7:20
@@ -34,6 +35,7 @@ note: cycle used when checking item types in module `m`
    |
 LL | mod m {
    | ^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `auto_trait_leakage3[211d]::m::Foo::{opaque#0}` satisfies auto traits
   --> $DIR/auto-trait-leakage3.rs:16:17
diff --git a/tests/ui/type-alias-impl-trait/defined-by-user-annotation.rs b/tests/ui/type-alias-impl-trait/defined-by-user-annotation.rs
new file mode 100644
index 00000000000..5a421ea1dc0
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/defined-by-user-annotation.rs
@@ -0,0 +1,19 @@
+// User type annotation in fn bodies is a a valid defining site for opaque types.
+// check-pass
+#![feature(type_alias_impl_trait)]
+
+trait Equate { type Proj; }
+impl<T> Equate for T { type Proj = T; }
+
+trait Indirect { type Ty; }
+impl<A, B: Equate<Proj = A>> Indirect for (A, B) { type Ty = (); }
+
+type Opq = impl Sized;
+fn define_1(_: Opq) {
+    let _ = None::<<(Opq, u8) as Indirect>::Ty>;
+}
+fn define_2() -> Opq {
+    0u8
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/inference-cycle.stderr b/tests/ui/type-alias-impl-trait/inference-cycle.stderr
index 4d5f367476b..41530dda983 100644
--- a/tests/ui/type-alias-impl-trait/inference-cycle.stderr
+++ b/tests/ui/type-alias-impl-trait/inference-cycle.stderr
@@ -16,6 +16,7 @@ note: cycle used when checking item types in module `m`
    |
 LL | mod m {
    | ^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `m::Foo::{opaque#0}`
   --> $DIR/inference-cycle.rs:5:20
@@ -34,6 +35,7 @@ note: cycle used when checking item types in module `m`
    |
 LL | mod m {
    | ^^^^^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `inference_cycle[4ecc]::m::Foo::{opaque#0}` satisfies auto traits
   --> $DIR/inference-cycle.rs:16:17
diff --git a/tests/ui/type-alias-impl-trait/issue-53092-2.stderr b/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
index 2565a28b493..6148131b491 100644
--- a/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-53092-2.stderr
@@ -23,6 +23,7 @@ LL | | type Bug<T, U> = impl Fn(T) -> U + Copy;
 LL | |     CONST_BUG(0);
 LL | | }
    | |_^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0277]: the trait bound `U: From<T>` is not satisfied
   --> $DIR/issue-53092-2.rs:9:5
diff --git a/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.rs b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.rs
new file mode 100644
index 00000000000..10588398c9d
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.rs
@@ -0,0 +1,21 @@
+// issue: 113314
+
+#![feature(type_alias_impl_trait)]
+
+type Op = impl std::fmt::Display;
+fn foo() -> Op { &"hello world" }
+
+fn transform<S>() -> impl std::fmt::Display {
+    &0usize
+}
+fn bad() -> Op {
+    transform::<Op>()
+    //~^ ERROR concrete type differs from previous defining opaque type use
+}
+
+fn main() {
+    let mut x = foo();
+    println!("{x}");
+    x = bad();
+    println!("{x}");
+}
diff --git a/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.stderr b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.stderr
new file mode 100644
index 00000000000..7481557fcba
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn-2.stderr
@@ -0,0 +1,14 @@
+error: concrete type differs from previous defining opaque type use
+  --> $DIR/recursive-tait-conflicting-defn-2.rs:12:5
+   |
+LL |     transform::<Op>()
+   |     ^^^^^^^^^^^^^^^^^ expected `&'static &'static str`, got `impl std::fmt::Display`
+   |
+note: previous use here
+  --> $DIR/recursive-tait-conflicting-defn-2.rs:6:18
+   |
+LL | fn foo() -> Op { &"hello world" }
+   |                  ^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.rs b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.rs
new file mode 100644
index 00000000000..e221f4f3f55
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.rs
@@ -0,0 +1,34 @@
+// issue: 113596
+
+#![feature(type_alias_impl_trait)]
+
+trait Test {}
+
+struct A;
+
+impl Test for A {}
+
+struct B<T> {
+  inner: T,
+}
+
+impl<T: Test> Test for B<T> {}
+
+type TestImpl = impl Test;
+
+fn test() -> TestImpl {
+  A
+}
+
+fn make_option() -> Option<TestImpl> {
+  Some(test())
+}
+
+fn make_option2() -> Option<TestImpl> {
+  let inner = make_option().unwrap();
+
+  Some(B { inner })
+  //~^ ERROR concrete type differs from previous defining opaque type use
+}
+
+fn main() {}
diff --git a/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.stderr b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.stderr
new file mode 100644
index 00000000000..e4209643b7a
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/recursive-tait-conflicting-defn.stderr
@@ -0,0 +1,14 @@
+error: concrete type differs from previous defining opaque type use
+  --> $DIR/recursive-tait-conflicting-defn.rs:30:3
+   |
+LL |   Some(B { inner })
+   |   ^^^^^^^^^^^^^^^^^ expected `A`, got `B<TestImpl>`
+   |
+note: previous use here
+  --> $DIR/recursive-tait-conflicting-defn.rs:20:3
+   |
+LL |   A
+   |   ^
+
+error: aborting due to previous error
+
diff --git a/tests/ui/type-alias-impl-trait/reveal_local.stderr b/tests/ui/type-alias-impl-trait/reveal_local.stderr
index 0c5ef4a6fb4..813185c1377 100644
--- a/tests/ui/type-alias-impl-trait/reveal_local.stderr
+++ b/tests/ui/type-alias-impl-trait/reveal_local.stderr
@@ -22,6 +22,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error[E0391]: cycle detected when computing type of `Foo::{opaque#0}`
   --> $DIR/reveal_local.rs:5:12
@@ -46,6 +47,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
   --> $DIR/reveal_local.rs:15:15
@@ -92,6 +94,7 @@ LL | |
 LL | |
 LL | | fn main() {}
    | |____________^
+   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: cannot check whether the hidden type of `reveal_local[9507]::Foo::{opaque#0}` satisfies auto traits
   --> $DIR/reveal_local.rs:25:15
diff --git a/triagebot.toml b/triagebot.toml
index 1a435ff074e..cc26c3b3e7b 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -457,7 +457,7 @@ cc = ["@davidtwco", "@compiler-errors", "@JohnTitor", "@TaKO8Ki"]
 
 [mentions."compiler/rustc_smir"]
 message = "This PR changes Stable MIR"
-cc = ["@oli-obk", "@celinval"]
+cc = ["@oli-obk", "@celinval", "@spastorino"]
 
 [mentions."compiler/rustc_target/src/spec"]
 message = """