Auto merge of #136135 - GuillaumeGomez:rollup-1ik636d, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - #135773 (Clarify WindowsMut (Lending)Iterator)
 - #135807 (Implement phantom variance markers)
 - #135876 (fix doc for std::sync::mpmc)
 - #135988 (Add a workaround for parallel rustc crashing when there are delayed bugs)
 - #136037 (Mark all NuttX targets as tier 3 target and support the standard library)
 - #136064 (Add a suggestion to cast target_feature fn items to fn pointers.)
 - #136082 (Incorporate `iter_nodes` into `graph::DirectedGraph`)
 - #136112 (Clean up all dead files inside `tests/ui/`)
 - #136114 (Use identifiers more in diagnostics code)
 - #136118 (Change `collect_and_partition_mono_items` tuple return type to a struct)

r? `@ghost`
`@rustbot` modify labels: rollup

65 files changed, 215 insertions, 186 deletions

diff --git a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
index 49706db0e0b..82417a86dd9 100644
--- a/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
+++ b/compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs
@@ -157,7 +157,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
         {
             cx.dcx().emit_err(RequiresMaybeSized {
                 span: pointee_ty_ident.span,
-                name: pointee_ty_ident.name.to_ident_string(),
+                name: pointee_ty_ident,
             });
             return;
         }
@@ -471,5 +471,5 @@ struct TooManyPointees {
 struct RequiresMaybeSized {
     #[primary_span]
     span: Span,
-    name: String,
+    name: Ident,
 }
diff --git a/compiler/rustc_codegen_cranelift/src/driver/aot.rs b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
index 7d5592daac1..27adf6318e2 100644
--- a/compiler/rustc_codegen_cranelift/src/driver/aot.rs
+++ b/compiler/rustc_codegen_cranelift/src/driver/aot.rs
@@ -676,7 +676,7 @@ pub(crate) fn run_aot(
     .to_owned();
 
     let cgus = if tcx.sess.opts.output_types.should_codegen() {
-        tcx.collect_and_partition_mono_items(()).1
+        tcx.collect_and_partition_mono_items(()).codegen_units
     } else {
         // If only `--emit metadata` is used, we shouldn't perform any codegen.
         // Also `tcx.collect_and_partition_mono_items` may panic in that case.
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index b3ad2a0e409..fd22421c7fc 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -9,6 +9,7 @@ use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_index::IndexVec;
 use rustc_middle::mir;
+use rustc_middle::mir::mono::MonoItemPartitions;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::RemapFileNameExt;
 use rustc_session::config::RemapPathScopeComponents;
@@ -297,12 +298,13 @@ struct UsageSets<'tcx> {
 /// Prepare sets of definitions that are relevant to deciding whether something
 /// is an "unused function" for coverage purposes.
 fn prepare_usage_sets<'tcx>(tcx: TyCtxt<'tcx>) -> UsageSets<'tcx> {
-    let (all_mono_items, cgus) = tcx.collect_and_partition_mono_items(());
+    let MonoItemPartitions { all_mono_items, codegen_units } =
+        tcx.collect_and_partition_mono_items(());
 
     // Obtain a MIR body for each function participating in codegen, via an
     // arbitrary instance.
     let mut def_ids_seen = FxHashSet::default();
-    let def_and_mir_for_all_mono_fns = cgus
+    let def_and_mir_for_all_mono_fns = codegen_units
         .iter()
         .flat_map(|cgu| cgu.items().keys())
         .filter_map(|item| match item {
diff --git a/compiler/rustc_codegen_ssa/src/assert_module_sources.rs b/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
index ab65319e3d3..27331ce4ca6 100644
--- a/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
+++ b/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
@@ -46,8 +46,12 @@ pub fn assert_module_sources(tcx: TyCtxt<'_>, set_reuse: &dyn Fn(&mut CguReuseTr
             return;
         }
 
-        let available_cgus =
-            tcx.collect_and_partition_mono_items(()).1.iter().map(|cgu| cgu.name()).collect();
+        let available_cgus = tcx
+            .collect_and_partition_mono_items(())
+            .codegen_units
+            .iter()
+            .map(|cgu| cgu.name())
+            .collect();
 
         let mut ams = AssertModuleSource {
             tcx,
diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 60ab2919352..f8f7bb2dbc6 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -293,7 +293,7 @@ fn exported_symbols_provider_local(
         // external linkage is enough for monomorphization to be linked to.
         let need_visibility = tcx.sess.target.dynamic_linking && !tcx.sess.target.only_cdylib;
 
-        let (_, cgus) = tcx.collect_and_partition_mono_items(());
+        let cgus = tcx.collect_and_partition_mono_items(()).codegen_units;
 
         // The symbols created in this loop are sorted below it
         #[allow(rustc::potential_query_instability)]
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 014bdeb46ad..e438bd70c51 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -619,7 +619,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
     // Run the monomorphization collector and partition the collected items into
     // codegen units.
-    let codegen_units = tcx.collect_and_partition_mono_items(()).1;
+    let codegen_units = tcx.collect_and_partition_mono_items(()).codegen_units;
 
     // Force all codegen_unit queries so they are already either red or green
     // when compile_codegen_unit accesses them. We are not able to re-execute
@@ -1051,7 +1051,7 @@ pub(crate) fn provide(providers: &mut Providers) {
             config::OptLevel::SizeMin => config::OptLevel::Default,
         };
 
-        let (defids, _) = tcx.collect_and_partition_mono_items(cratenum);
+        let defids = tcx.collect_and_partition_mono_items(cratenum).all_mono_items;
 
         let any_for_speed = defids.items().any(|id| {
             let CodegenFnAttrs { optimize, .. } = tcx.codegen_fn_attrs(*id);
diff --git a/compiler/rustc_data_structures/src/graph/mod.rs b/compiler/rustc_data_structures/src/graph/mod.rs
index 92035e8bc48..4a1e5db6768 100644
--- a/compiler/rustc_data_structures/src/graph/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/mod.rs
@@ -14,7 +14,23 @@ mod tests;
 pub trait DirectedGraph {
     type Node: Idx;
 
+    /// Returns the total number of nodes in this graph.
+    ///
+    /// Several graph algorithm implementations assume that every node ID is
+    /// strictly less than the number of nodes, i.e. nodes are densely numbered.
+    /// That assumption allows them to use `num_nodes` to allocate per-node
+    /// data structures, indexed by node.
     fn num_nodes(&self) -> usize;
+
+    /// Iterates over all nodes of a graph in ascending numeric order.
+    ///
+    /// Assumes that nodes are densely numbered, i.e. every index in
+    /// `0..num_nodes` is a valid node.
+    fn iter_nodes(
+        &self,
+    ) -> impl Iterator<Item = Self::Node> + DoubleEndedIterator + ExactSizeIterator {
+        (0..self.num_nodes()).map(<Self::Node as Idx>::new)
+    }
 }
 
 pub trait NumEdges: DirectedGraph {
diff --git a/compiler/rustc_data_structures/src/graph/scc/mod.rs b/compiler/rustc_data_structures/src/graph/scc/mod.rs
index 06fedef00fc..93f6192b10b 100644
--- a/compiler/rustc_data_structures/src/graph/scc/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/scc/mod.rs
@@ -333,8 +333,8 @@ where
             to_annotation,
         };
 
-        let scc_indices = (0..num_nodes)
-            .map(G::Node::new)
+        let scc_indices = graph
+            .iter_nodes()
             .map(|node| match this.start_walk_from(node) {
                 WalkReturn::Complete { scc_index, .. } => scc_index,
                 WalkReturn::Cycle { min_depth, .. } => {
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 dbc5c634c45..d2ab98bae89 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -2362,7 +2362,7 @@ fn try_report_async_mismatch<'tcx>(
             // the right span is a bit difficult.
             return Err(tcx.sess.dcx().emit_err(MethodShouldReturnFuture {
                 span: tcx.def_span(impl_m.def_id),
-                method_name: trait_m.name,
+                method_name: tcx.item_ident(impl_m.def_id),
                 trait_item_span: tcx.hir().span_if_local(trait_m.def_id),
             }));
         }
diff --git a/compiler/rustc_hir_analysis/src/check/mod.rs b/compiler/rustc_hir_analysis/src/check/mod.rs
index 92b18c80fd8..69b4aa47eba 100644
--- a/compiler/rustc_hir_analysis/src/check/mod.rs
+++ b/compiler/rustc_hir_analysis/src/check/mod.rs
@@ -197,7 +197,7 @@ fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: LocalDefId) {
 
 fn report_forbidden_specialization(tcx: TyCtxt<'_>, impl_item: DefId, parent_impl: DefId) {
     let span = tcx.def_span(impl_item);
-    let ident = tcx.item_name(impl_item);
+    let ident = tcx.item_ident(impl_item);
 
     let err = match tcx.span_of_impl(parent_impl) {
         Ok(sp) => errors::ImplNotMarkedDefault::Ok { span, ident, ok_label: sp },
@@ -297,7 +297,7 @@ fn default_body_is_unstable(
     reason: Option<Symbol>,
     issue: Option<NonZero<u32>>,
 ) {
-    let missing_item_name = tcx.associated_item(item_did).name;
+    let missing_item_name = tcx.item_ident(item_did);
     let (mut some_note, mut none_note, mut reason_str) = (false, false, String::new());
     match reason {
         Some(r) => {
diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index b43a808ccdc..27a7c2ea530 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -292,7 +292,7 @@ fn visit_implementation_of_dispatch_from_dyn(checker: &Checker<'_>) -> Result<()
 
                         res = Err(tcx.dcx().emit_err(errors::DispatchFromDynZST {
                             span,
-                            name: field.name,
+                            name: field.ident(tcx),
                             ty: ty_a,
                         }));
 
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index d17ee86ba66..dbf7a7378f5 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -465,8 +465,8 @@ fn emit_orphan_check_error<'tcx>(
         traits::OrphanCheckErr::UncoveredTyParams(UncoveredTyParams { uncovered, local_ty }) => {
             let mut reported = None;
             for param_def_id in uncovered {
-                let span = tcx.def_ident_span(param_def_id).unwrap();
-                let name = tcx.item_name(param_def_id);
+                let name = tcx.item_ident(param_def_id);
+                let span = name.span;
 
                 reported.get_or_insert(match local_ty {
                     Some(local_type) => tcx.dcx().emit_err(errors::TyParamFirstLocal {
@@ -492,7 +492,7 @@ fn lint_uncovered_ty_params<'tcx>(
 
     for param_def_id in uncovered {
         let span = tcx.def_ident_span(param_def_id).unwrap();
-        let name = tcx.item_name(param_def_id);
+        let name = tcx.item_ident(param_def_id);
 
         match local_ty {
             Some(local_type) => tcx.emit_node_span_lint(
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index c517d25fcbf..447050ea7d2 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -928,7 +928,7 @@ fn lower_enum_variant_types(tcx: TyCtxt<'_>, def_id: DefId) {
                 tcx.dcx().emit_err(errors::EnumDiscriminantOverflowed {
                     span,
                     discr: prev_discr.unwrap().to_string(),
-                    item_name: tcx.item_name(variant.def_id),
+                    item_name: tcx.item_ident(variant.def_id),
                     wrapped_discr: wrapped_discr.to_string(),
                 });
                 None
@@ -990,11 +990,10 @@ impl<'tcx> FieldUniquenessCheckContext<'tcx> {
     }
 
     /// Check if a given field `ident` declared at `field_decl` has been declared elsewhere before.
-    fn check_field_decl(&mut self, ident: Ident, field_decl: FieldDeclSpan) {
+    fn check_field_decl(&mut self, field_name: Ident, field_decl: FieldDeclSpan) {
         use FieldDeclSpan::*;
-        let field_name = ident.name;
-        let ident = ident.normalize_to_macros_2_0();
-        match (field_decl, self.seen_fields.get(&ident).copied()) {
+        let field_name = field_name.normalize_to_macros_2_0();
+        match (field_decl, self.seen_fields.get(&field_name).copied()) {
             (NotNested(span), Some(NotNested(prev_span))) => {
                 self.tcx.dcx().emit_err(errors::FieldAlreadyDeclared::NotNested {
                     field_name,
@@ -1035,7 +1034,7 @@ impl<'tcx> FieldUniquenessCheckContext<'tcx> {
                 });
             }
             (field_decl, None) => {
-                self.seen_fields.insert(ident, field_decl);
+                self.seen_fields.insert(field_name, field_decl);
             }
         }
     }
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
index d1a1e36c1d5..e2b9fe0f9f7 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
@@ -55,7 +55,7 @@ pub(super) fn find_opaque_ty_constraints_for_impl_trait_in_assoc_type(
     } else {
         let reported = tcx.dcx().emit_err(UnconstrainedOpaqueType {
             span: tcx.def_span(def_id),
-            name: tcx.item_name(parent_def_id.to_def_id()),
+            name: tcx.item_ident(parent_def_id.to_def_id()),
             what: "impl",
         });
         Ty::new_error(tcx, reported)
@@ -136,7 +136,7 @@ pub(super) fn find_opaque_ty_constraints_for_tait(tcx: TyCtxt<'_>, def_id: Local
         }
         let reported = tcx.dcx().emit_err(UnconstrainedOpaqueType {
             span: tcx.def_span(def_id),
-            name: tcx.item_name(parent_def_id.to_def_id()),
+            name: tcx.item_ident(parent_def_id.to_def_id()),
             what: match tcx.hir_node(scope) {
                 _ if scope == hir::CRATE_HIR_ID => "module",
                 Node::Item(hir::Item { kind: hir::ItemKind::Mod(_), .. }) => "module",
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index a0f365142ba..1dcea5d0335 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -217,7 +217,7 @@ pub(crate) struct DropImplOnWrongItem {
 pub(crate) enum FieldAlreadyDeclared {
     #[diag(hir_analysis_field_already_declared, code = E0124)]
     NotNested {
-        field_name: Symbol,
+        field_name: Ident,
         #[primary_span]
         #[label]
         span: Span,
@@ -226,7 +226,7 @@ pub(crate) enum FieldAlreadyDeclared {
     },
     #[diag(hir_analysis_field_already_declared_current_nested)]
     CurrentNested {
-        field_name: Symbol,
+        field_name: Ident,
         #[primary_span]
         #[label]
         span: Span,
@@ -239,7 +239,7 @@ pub(crate) enum FieldAlreadyDeclared {
     },
     #[diag(hir_analysis_field_already_declared_previous_nested)]
     PreviousNested {
-        field_name: Symbol,
+        field_name: Ident,
         #[primary_span]
         #[label]
         span: Span,
@@ -252,7 +252,7 @@ pub(crate) enum FieldAlreadyDeclared {
     },
     #[diag(hir_analysis_field_already_declared_both_nested)]
     BothNested {
-        field_name: Symbol,
+        field_name: Ident,
         #[primary_span]
         #[label]
         span: Span,
@@ -418,7 +418,7 @@ pub(crate) struct ValueOfAssociatedStructAlreadySpecified {
 pub(crate) struct UnconstrainedOpaqueType {
     #[primary_span]
     pub span: Span,
-    pub name: Symbol,
+    pub name: Ident,
     pub what: &'static str,
 }
 
@@ -802,7 +802,7 @@ pub(crate) struct EnumDiscriminantOverflowed {
     #[label]
     pub span: Span,
     pub discr: String,
-    pub item_name: Symbol,
+    pub item_name: Ident,
     pub wrapped_discr: String,
 }
 
@@ -893,7 +893,7 @@ pub(crate) enum ImplNotMarkedDefault {
         span: Span,
         #[label(hir_analysis_ok_label)]
         ok_label: Span,
-        ident: Symbol,
+        ident: Ident,
     },
     #[diag(hir_analysis_impl_not_marked_default_err, code = E0520)]
     #[note]
@@ -901,7 +901,7 @@ pub(crate) enum ImplNotMarkedDefault {
         #[primary_span]
         span: Span,
         cname: Symbol,
-        ident: Symbol,
+        ident: Ident,
     },
 }
 
@@ -977,7 +977,7 @@ pub(crate) struct MissingTraitItemUnstable {
     pub some_note: bool,
     #[note(hir_analysis_none_note)]
     pub none_note: bool,
-    pub missing_item_name: Symbol,
+    pub missing_item_name: Ident,
     pub feature: Symbol,
     pub reason: String,
 }
@@ -1249,7 +1249,7 @@ pub(crate) struct InherentNominal {
 pub(crate) struct DispatchFromDynZST<'a> {
     #[primary_span]
     pub span: Span,
-    pub name: Symbol,
+    pub name: Ident,
     pub ty: Ty<'a>,
 }
 
@@ -1389,7 +1389,7 @@ pub(crate) struct TyParamFirstLocal<'tcx> {
     pub span: Span,
     #[note(hir_analysis_case_note)]
     pub note: (),
-    pub param: Symbol,
+    pub param: Ident,
     pub local_type: Ty<'tcx>,
 }
 
@@ -1401,7 +1401,7 @@ pub(crate) struct TyParamFirstLocalLint<'tcx> {
     pub span: Span,
     #[note(hir_analysis_case_note)]
     pub note: (),
-    pub param: Symbol,
+    pub param: Ident,
     pub local_type: Ty<'tcx>,
 }
 
@@ -1414,7 +1414,7 @@ pub(crate) struct TyParamSome {
     pub span: Span,
     #[note(hir_analysis_only_note)]
     pub note: (),
-    pub param: Symbol,
+    pub param: Ident,
 }
 
 #[derive(LintDiagnostic)]
@@ -1425,7 +1425,7 @@ pub(crate) struct TyParamSomeLint {
     pub span: Span,
     #[note(hir_analysis_only_note)]
     pub note: (),
-    pub param: Symbol,
+    pub param: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -1533,7 +1533,7 @@ pub(crate) struct UnsupportedDelegation<'a> {
 pub(crate) struct MethodShouldReturnFuture {
     #[primary_span]
     pub span: Span,
-    pub method_name: Symbol,
+    pub method_name: Ident,
     #[note]
     pub trait_item_span: Option<Span>,
 }
@@ -1585,7 +1585,7 @@ pub(crate) struct UnconstrainedGenericParameter {
     #[primary_span]
     #[label]
     pub span: Span,
-    pub param_name: Symbol,
+    pub param_name: Ident,
     pub param_def_kind: &'static str,
     #[note(hir_analysis_const_param_note)]
     pub const_param_note: bool,
diff --git a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
index 5ae7944f6d5..67407349729 100644
--- a/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
+++ b/compiler/rustc_hir_analysis/src/errors/wrong_number_of_generic_args.rs
@@ -495,7 +495,7 @@ impl<'a, 'tcx> WrongNumberOfGenericArgs<'a, 'tcx> {
                         .iter()
                         .any(|constraint| constraint.ident.name == item.name)
                 })
-                .map(|item| item.name.to_ident_string())
+                .map(|item| self.tcx.item_ident(item.def_id).to_string())
                 .collect()
         } else {
             Vec::default()
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index 42034736ad6..fd5a7089b4c 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -152,7 +152,7 @@ pub(crate) fn enforce_impl_lifetime_params_are_constrained(
                 {
                     let mut diag = tcx.dcx().create_err(UnconstrainedGenericParameter {
                         span: tcx.def_span(param.def_id),
-                        param_name: param.name,
+                        param_name: tcx.item_ident(param.def_id),
                         param_def_kind: tcx.def_descr(param.def_id),
                         const_param_note: false,
                         const_param_note2: false,
@@ -223,7 +223,7 @@ pub(crate) fn enforce_impl_non_lifetime_params_are_constrained(
             let const_param_note = matches!(param.kind, ty::GenericParamDefKind::Const { .. });
             let mut diag = tcx.dcx().create_err(UnconstrainedGenericParameter {
                 span: tcx.def_span(param.def_id),
-                param_name: param.name,
+                param_name: tcx.item_ident(param.def_id),
                 param_def_kind: tcx.def_descr(param.def_id),
                 const_param_note,
                 const_param_note2: const_param_note,
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index bdd436302f4..1c828591bcb 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -3337,10 +3337,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 })
                 .map(|mut field_path| {
                     field_path.pop();
-                    field_path
-                        .iter()
-                        .map(|id| format!("{}.", id.name.to_ident_string()))
-                        .collect::<String>()
+                    field_path.iter().map(|id| format!("{}.", id)).collect::<String>()
                 })
                 .collect::<Vec<_>>();
             candidate_fields.sort();
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index c9e55695e5d..07e013e4afa 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -453,7 +453,7 @@ fn report_unexpected_variant_res(
                 );
                 let fields = fields
                     .iter()
-                    .map(|field| format!("{}: _", field.name.to_ident_string()))
+                    .map(|field| format!("{}: _", field.ident(tcx)))
                     .collect::<Vec<_>>()
                     .join(", ");
                 let sugg = format!(" {{ {} }}", fields);
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 89843da9d7b..5d4e67d1a0e 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -2714,7 +2714,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     .map(|field_path| {
                         field_path
                             .iter()
-                            .map(|id| id.name.to_ident_string())
+                            .map(|id| id.to_string())
                             .collect::<Vec<String>>()
                             .join(".")
                     })
diff --git a/compiler/rustc_lint/src/dangling.rs b/compiler/rustc_lint/src/dangling.rs
index 98b717a3070..fd6b3e90ada 100644
--- a/compiler/rustc_lint/src/dangling.rs
+++ b/compiler/rustc_lint/src/dangling.rs
@@ -141,7 +141,7 @@ fn lint_expr(cx: &LateContext<'_>, expr: &Expr<'_>) {
             expr.hir_id,
             method.ident.span,
             DanglingPointersFromTemporaries {
-                callee: method.ident.name,
+                callee: method.ident,
                 ty,
                 ptr_span: method.ident.span,
                 temporary_span: receiver.span,
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index 677fc86a235..09b0e1ed8bd 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -1150,7 +1150,7 @@ pub(crate) struct IgnoredUnlessCrateSpecified<'a> {
 #[help(lint_help_visit)]
 // FIXME: put #[primary_span] on `ptr_span` once it does not cause conflicts
 pub(crate) struct DanglingPointersFromTemporaries<'tcx> {
-    pub callee: Symbol,
+    pub callee: Ident,
     pub ty: Ty<'tcx>,
     #[label(lint_label_ptr)]
     pub ptr_span: Span,
@@ -1351,7 +1351,7 @@ pub(crate) enum NonUpperCaseGlobalSub {
 #[diag(lint_noop_method_call)]
 #[note]
 pub(crate) struct NoopMethodCallDiag<'a> {
-    pub method: Symbol,
+    pub method: Ident,
     pub orig_ty: Ty<'a>,
     pub trait_: Symbol,
     #[suggestion(code = "", applicability = "machine-applicable")]
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index 1bf19047ade..4e9d793be5b 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -343,5 +343,5 @@ fn path_span_without_args(path: &Path<'_>) -> Span {
 
 /// Return a "error message-able" ident for the last segment of the `Path`
 fn path_name_to_string(path: &Path<'_>) -> String {
-    path.segments.last().unwrap().ident.name.to_ident_string()
+    path.segments.last().unwrap().ident.to_string()
 }
diff --git a/compiler/rustc_lint/src/noop_method_call.rs b/compiler/rustc_lint/src/noop_method_call.rs
index fa519281be5..790ef910b04 100644
--- a/compiler/rustc_lint/src/noop_method_call.rs
+++ b/compiler/rustc_lint/src/noop_method_call.rs
@@ -129,7 +129,7 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
                 _ => None,
             };
             cx.emit_span_lint(NOOP_METHOD_CALL, span, NoopMethodCallDiag {
-                method: call.ident.name,
+                method: call.ident,
                 orig_ty,
                 trait_,
                 label: span,
diff --git a/compiler/rustc_lint/src/pass_by_value.rs b/compiler/rustc_lint/src/pass_by_value.rs
index 244cd358e9c..a1d66047058 100644
--- a/compiler/rustc_lint/src/pass_by_value.rs
+++ b/compiler/rustc_lint/src/pass_by_value.rs
@@ -45,7 +45,7 @@ fn path_for_pass_by_value(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> Option<Stri
     if let TyKind::Path(QPath::Resolved(_, path)) = &ty.kind {
         match path.res {
             Res::Def(_, def_id) if cx.tcx.has_attr(def_id, sym::rustc_pass_by_value) => {
-                let name = cx.tcx.item_name(def_id).to_ident_string();
+                let name = cx.tcx.item_ident(def_id);
                 let path_segment = path.segments.last().unwrap();
                 return Some(format!("{}{}", name, gen_args(cx, path_segment)));
             }
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 111c3b6956a..3eccf56d8c4 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -8,7 +8,7 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::stable_hasher::{Hash128, HashStable, StableHasher, ToStableHashKey};
 use rustc_data_structures::unord::UnordMap;
 use rustc_hir::ItemId;
-use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdSet, LOCAL_CRATE};
 use rustc_index::Idx;
 use rustc_macros::{HashStable, TyDecodable, TyEncodable};
 use rustc_query_system::ich::StableHashingContext;
@@ -247,6 +247,12 @@ impl ToStableHashKey<StableHashingContext<'_>> for MonoItem<'_> {
     }
 }
 
+#[derive(Debug, HashStable, Copy, Clone)]
+pub struct MonoItemPartitions<'tcx> {
+    pub codegen_units: &'tcx [CodegenUnit<'tcx>],
+    pub all_mono_items: &'tcx DefIdSet,
+}
+
 #[derive(Debug, HashStable)]
 pub struct CodegenUnit<'tcx> {
     /// A name for this CGU. Incremental compilation requires that
diff --git a/compiler/rustc_middle/src/query/erase.rs b/compiler/rustc_middle/src/query/erase.rs
index 1676afb4b6e..14f871cbbdc 100644
--- a/compiler/rustc_middle/src/query/erase.rs
+++ b/compiler/rustc_middle/src/query/erase.rs
@@ -349,6 +349,7 @@ tcx_lifetime! {
     rustc_middle::mir::interpret::GlobalId,
     rustc_middle::mir::interpret::LitToConstInput,
     rustc_middle::mir::interpret::EvalStaticInitializerRawResult,
+    rustc_middle::mir::mono::MonoItemPartitions,
     rustc_middle::traits::query::MethodAutoderefStepsResult,
     rustc_middle::traits::query::type_op::AscribeUserType,
     rustc_middle::traits::query::type_op::Eq,
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 17e1fe35bba..e27a9823639 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -23,7 +23,7 @@ use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def::{DefKind, DocLinkResMap};
 use rustc_hir::def_id::{
-    CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LocalDefIdMap, LocalDefIdSet, LocalModDefId,
+    CrateNum, DefId, DefIdMap, LocalDefId, LocalDefIdMap, LocalDefIdSet, LocalModDefId,
 };
 use rustc_hir::lang_items::{LangItem, LanguageItems};
 use rustc_hir::{Crate, ItemLocalId, ItemLocalMap, TraitCandidate};
@@ -58,7 +58,7 @@ use crate::mir::interpret::{
     EvalStaticInitializerRawResult, EvalToAllocationRawResult, EvalToConstValueResult,
     EvalToValTreeResult, GlobalId, LitToConstInput,
 };
-use crate::mir::mono::{CodegenUnit, CollectionMode, MonoItem};
+use crate::mir::mono::{CodegenUnit, CollectionMode, MonoItem, MonoItemPartitions};
 use crate::query::erase::{Erase, erase, restore};
 use crate::query::plumbing::{
     CyclePlaceholder, DynamicQuery, query_ensure, query_ensure_error_guaranteed, query_get_at,
@@ -2166,7 +2166,7 @@ rustc_queries! {
         separate_provide_extern
     }
 
-    query collect_and_partition_mono_items(_: ()) -> (&'tcx DefIdSet, &'tcx [CodegenUnit<'tcx>]) {
+    query collect_and_partition_mono_items(_: ()) -> MonoItemPartitions<'tcx> {
         eval_always
         desc { "collect_and_partition_mono_items" }
     }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index d1079743004..1f0710e2415 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1349,6 +1349,33 @@ pub struct GlobalCtxt<'tcx> {
 
     /// Stores memory for globals (statics/consts).
     pub(crate) alloc_map: Lock<interpret::AllocMap<'tcx>>,
+
+    current_gcx: CurrentGcx,
+}
+
+impl<'tcx> GlobalCtxt<'tcx> {
+    /// Installs `self` in a `TyCtxt` and `ImplicitCtxt` for the duration of
+    /// `f`.
+    pub fn enter<F, R>(&'tcx self, f: F) -> R
+    where
+        F: FnOnce(TyCtxt<'tcx>) -> R,
+    {
+        let icx = tls::ImplicitCtxt::new(self);
+
+        // Reset `current_gcx` to `None` when we exit.
+        let _on_drop = defer(move || {
+            *self.current_gcx.value.write() = None;
+        });
+
+        // Set this `GlobalCtxt` as the current one.
+        {
+            let mut guard = self.current_gcx.value.write();
+            assert!(guard.is_none(), "no `GlobalCtxt` is currently set");
+            *guard = Some(self as *const _ as *const ());
+        }
+
+        tls::enter_context(&icx, || f(icx.tcx))
+    }
 }
 
 /// This is used to get a reference to a `GlobalCtxt` if one is available.
@@ -1539,23 +1566,11 @@ impl<'tcx> TyCtxt<'tcx> {
             canonical_param_env_cache: Default::default(),
             data_layout,
             alloc_map: Lock::new(interpret::AllocMap::new()),
+            current_gcx,
         });
 
-        let icx = tls::ImplicitCtxt::new(&gcx);
-
-        // Reset `current_gcx` to `None` when we exit.
-        let _on_drop = defer(|| {
-            *current_gcx.value.write() = None;
-        });
-
-        // Set this `GlobalCtxt` as the current one.
-        {
-            let mut guard = current_gcx.value.write();
-            assert!(guard.is_none(), "no `GlobalCtxt` is currently set");
-            *guard = Some(&gcx as *const _ as *const ());
-        }
-
-        tls::enter_context(&icx, || f(icx.tcx))
+        // This is a separate function to work around a crash with parallel rustc (#135870)
+        gcx.enter(f)
     }
 
     /// Obtain all lang items of this crate and all dependencies (recursively)
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index ca70ae794c5..8cd632790a8 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1596,6 +1596,15 @@ impl<'tcx> TyCtxt<'tcx> {
         Some(Ident::new(def, span))
     }
 
+    /// Look up the name and span of a definition.
+    ///
+    /// See [`item_name`][Self::item_name] for more information.
+    pub fn item_ident(self, def_id: DefId) -> Ident {
+        self.opt_item_ident(def_id).unwrap_or_else(|| {
+            bug!("item_ident: no name for {:?}", self.def_path(def_id));
+        })
+    }
+
     pub fn opt_associated_item(self, def_id: DefId) -> Option<AssocItem> {
         if let DefKind::AssocConst | DefKind::AssocFn | DefKind::AssocTy = self.def_kind(def_id) {
             Some(self.associated_item(def_id))
diff --git a/compiler/rustc_mir_build/src/errors.rs b/compiler/rustc_mir_build/src/errors.rs
index c3bf5868eec..1f87bf0dbbb 100644
--- a/compiler/rustc_mir_build/src/errors.rs
+++ b/compiler/rustc_mir_build/src/errors.rs
@@ -7,7 +7,7 @@ use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::{self, Ty};
 use rustc_pattern_analysis::errors::Uncovered;
 use rustc_pattern_analysis::rustc::RustcPatCtxt;
-use rustc_span::{Span, Symbol};
+use rustc_span::{Ident, Span, Symbol};
 
 use crate::fluent_generated as fluent;
 
@@ -753,7 +753,7 @@ pub(crate) struct BindingsWithVariantName {
     #[suggestion(code = "{ty_path}::{name}", applicability = "machine-applicable")]
     pub(crate) suggestion: Option<Span>,
     pub(crate) ty_path: String,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
 }
 
 #[derive(LintDiagnostic)]
@@ -797,7 +797,7 @@ pub(crate) struct BorrowOfMovedValue {
     pub(crate) binding_span: Span,
     #[label(mir_build_value_borrowed_label)]
     pub(crate) conflicts_ref: Vec<Span>,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
     pub(crate) ty: String,
     #[suggestion(code = "ref ", applicability = "machine-applicable")]
     pub(crate) suggest_borrowing: Option<Span>,
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index d8b04398d9a..e0a1117f905 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -25,7 +25,7 @@ use rustc_session::lint::builtin::{
 };
 use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::hygiene::DesugaringKind;
-use rustc_span::{Span, sym};
+use rustc_span::{Ident, Span, sym};
 use rustc_trait_selection::infer::InferCtxtExt;
 use tracing::instrument;
 
@@ -800,7 +800,7 @@ fn check_borrow_conflicts_in_at_patterns<'tcx>(cx: &MatchVisitor<'_, 'tcx>, pat:
                 sess.dcx().emit_err(BorrowOfMovedValue {
                     binding_span: pat.span,
                     conflicts_ref,
-                    name,
+                    name: Ident::new(name, pat.span),
                     ty,
                     suggest_borrowing: Some(pat.span.shrink_to_lo()),
                     has_path: path.is_some(),
@@ -908,7 +908,7 @@ fn check_for_bindings_named_same_as_variants(
                     None
                 },
                 ty_path,
-                name,
+                name: Ident::new(name, pat.span),
             },
         )
     }
diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs
index 50ebde3292e..adb99a75a9e 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters.rs
@@ -10,14 +10,12 @@ use rustc_index::bit_set::DenseBitSet;
 use rustc_middle::mir::coverage::{CounterId, CovTerm, Expression, ExpressionId, Op};
 
 use crate::coverage::counters::balanced_flow::BalancedFlowGraph;
-use crate::coverage::counters::iter_nodes::IterNodes;
 use crate::coverage::counters::node_flow::{
     CounterTerm, NodeCounters, make_node_counters, node_flow_data_for_balanced_graph,
 };
 use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph};
 
 mod balanced_flow;
-mod iter_nodes;
 mod node_flow;
 mod union_find;
 
diff --git a/compiler/rustc_mir_transform/src/coverage/counters/balanced_flow.rs b/compiler/rustc_mir_transform/src/coverage/counters/balanced_flow.rs
index c108f96a564..4c20722a043 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters/balanced_flow.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters/balanced_flow.rs
@@ -20,8 +20,6 @@ use rustc_data_structures::graph::reversed::ReversedGraph;
 use rustc_index::Idx;
 use rustc_index::bit_set::DenseBitSet;
 
-use crate::coverage::counters::iter_nodes::IterNodes;
-
 /// A view of an underlying graph that has been augmented to have “balanced flow”.
 /// This means that the flow (execution count) of each node is equal to the
 /// sum of its in-edge flows, and also equal to the sum of its out-edge flows.
diff --git a/compiler/rustc_mir_transform/src/coverage/counters/iter_nodes.rs b/compiler/rustc_mir_transform/src/coverage/counters/iter_nodes.rs
deleted file mode 100644
index 9d87f7af1b0..00000000000
--- a/compiler/rustc_mir_transform/src/coverage/counters/iter_nodes.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-use rustc_data_structures::graph;
-use rustc_index::Idx;
-
-pub(crate) trait IterNodes: graph::DirectedGraph {
-    /// Iterates over all nodes of a graph in ascending numeric order.
-    /// Assumes that nodes are densely numbered, i.e. every index in
-    /// `0..num_nodes` is a valid node.
-    ///
-    /// FIXME: Can this just be part of [`graph::DirectedGraph`]?
-    fn iter_nodes(
-        &self,
-    ) -> impl Iterator<Item = Self::Node> + DoubleEndedIterator + ExactSizeIterator {
-        (0..self.num_nodes()).map(<Self::Node as Idx>::new)
-    }
-}
-impl<G: graph::DirectedGraph> IterNodes for G {}
diff --git a/compiler/rustc_mir_transform/src/coverage/counters/node_flow.rs b/compiler/rustc_mir_transform/src/coverage/counters/node_flow.rs
index 3647c889937..9d80b3af42d 100644
--- a/compiler/rustc_mir_transform/src/coverage/counters/node_flow.rs
+++ b/compiler/rustc_mir_transform/src/coverage/counters/node_flow.rs
@@ -11,7 +11,6 @@ use rustc_index::bit_set::DenseBitSet;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use rustc_middle::mir::coverage::Op;
 
-use crate::coverage::counters::iter_nodes::IterNodes;
 use crate::coverage::counters::union_find::UnionFind;
 
 #[cfg(test)]
diff --git a/compiler/rustc_mir_transform/src/errors.rs b/compiler/rustc_mir_transform/src/errors.rs
index a2fd46043ca..29698b0c2e4 100644
--- a/compiler/rustc_mir_transform/src/errors.rs
+++ b/compiler/rustc_mir_transform/src/errors.rs
@@ -5,7 +5,7 @@ use rustc_middle::mir::AssertKind;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::lint::{self, Lint};
 use rustc_span::def_id::DefId;
-use rustc_span::{Span, Symbol};
+use rustc_span::{Ident, Span, Symbol};
 
 use crate::fluent_generated as fluent;
 
@@ -114,7 +114,7 @@ pub(crate) struct FnItemRef {
     #[suggestion(code = "{sugg}", applicability = "unspecified")]
     pub span: Span,
     pub sugg: String,
-    pub ident: String,
+    pub ident: Ident,
 }
 
 #[derive(Diagnostic)]
diff --git a/compiler/rustc_mir_transform/src/function_item_references.rs b/compiler/rustc_mir_transform/src/function_item_references.rs
index fb21bf9977f..7e88925b2e1 100644
--- a/compiler/rustc_mir_transform/src/function_item_references.rs
+++ b/compiler/rustc_mir_transform/src/function_item_references.rs
@@ -168,7 +168,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
                 s
             }
         };
-        let ident = self.tcx.item_name(fn_id).to_ident_string();
+        let ident = self.tcx.item_ident(fn_id);
         let ty_params = fn_args.types().map(|ty| format!("{ty}"));
         let const_params = fn_args.consts().map(|c| format!("{c}"));
         let params = ty_params.chain(const_params).join(", ");
@@ -177,7 +177,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> {
         let ret = if fn_sig.output().skip_binder().is_unit() { "" } else { " -> _" };
         let sugg = format!(
             "{} as {}{}fn({}{}){}",
-            if params.is_empty() { ident.clone() } else { format!("{ident}::<{params}>") },
+            if params.is_empty() { ident.to_string() } else { format!("{ident}::<{params}>") },
             unsafety,
             abi,
             vec!["_"; num_args].join(", "),
diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index 7b179663430..e08c348a64d 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -110,7 +110,7 @@ use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
 use rustc_middle::middle::exported_symbols::{SymbolExportInfo, SymbolExportLevel};
 use rustc_middle::mir::mono::{
     CodegenUnit, CodegenUnitNameBuilder, InstantiationMode, Linkage, MonoItem, MonoItemData,
-    Visibility,
+    MonoItemPartitions, Visibility,
 };
 use rustc_middle::ty::print::{characteristic_def_id_of_type, with_no_trimmed_paths};
 use rustc_middle::ty::{self, InstanceKind, TyCtxt};
@@ -1114,7 +1114,7 @@ where
     }
 }
 
-fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> (&DefIdSet, &[CodegenUnit<'_>]) {
+fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> MonoItemPartitions<'_> {
     let collection_strategy = match tcx.sess.opts.unstable_opts.print_mono_items {
         Some(ref s) => {
             let mode = s.to_lowercase();
@@ -1236,7 +1236,7 @@ fn collect_and_partition_mono_items(tcx: TyCtxt<'_>, (): ()) -> (&DefIdSet, &[Co
         }
     }
 
-    (tcx.arena.alloc(mono_items), codegen_units)
+    MonoItemPartitions { all_mono_items: tcx.arena.alloc(mono_items), codegen_units }
 }
 
 /// Outputs stats about instantiation counts and estimated size, per `MonoItem`'s
@@ -1319,14 +1319,13 @@ fn dump_mono_items_stats<'tcx>(
 pub(crate) fn provide(providers: &mut Providers) {
     providers.collect_and_partition_mono_items = collect_and_partition_mono_items;
 
-    providers.is_codegened_item = |tcx, def_id| {
-        let (all_mono_items, _) = tcx.collect_and_partition_mono_items(());
-        all_mono_items.contains(&def_id)
-    };
+    providers.is_codegened_item =
+        |tcx, def_id| tcx.collect_and_partition_mono_items(()).all_mono_items.contains(&def_id);
 
     providers.codegen_unit = |tcx, name| {
-        let (_, all) = tcx.collect_and_partition_mono_items(());
-        all.iter()
+        tcx.collect_and_partition_mono_items(())
+            .codegen_units
+            .iter()
             .find(|cgu| cgu.name() == name)
             .unwrap_or_else(|| panic!("failed to find cgu with name {name:?}"))
     };
diff --git a/compiler/rustc_parse/src/errors.rs b/compiler/rustc_parse/src/errors.rs
index f78d9dc2bfc..50287b706ce 100644
--- a/compiler/rustc_parse/src/errors.rs
+++ b/compiler/rustc_parse/src/errors.rs
@@ -3233,7 +3233,7 @@ pub(crate) struct MalformedCfgAttr {
 pub(crate) struct UnknownBuiltinConstruct {
     #[primary_span]
     pub span: Span,
-    pub name: Symbol,
+    pub name: Ident,
 }
 
 #[derive(Diagnostic)]
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index 5cd02128287..a5b73ce4098 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -1958,7 +1958,7 @@ impl<'a> Parser<'a> {
         } else {
             let err = self.dcx().create_err(errors::UnknownBuiltinConstruct {
                 span: lo.to(ident.span),
-                name: ident.name,
+                name: ident,
             });
             return Err(err);
         };
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index ccd5b519cb0..8dc752c2cb3 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -677,7 +677,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 }
                 if could_be_path {
                     let import_suggestions = self.lookup_import_candidates(
-                        Ident::with_dummy_span(name),
+                        name,
                         Namespace::ValueNS,
                         &parent_scope,
                         &|res: Res| {
diff --git a/compiler/rustc_resolve/src/errors.rs b/compiler/rustc_resolve/src/errors.rs
index 3bfe98f7091..7eb795034b0 100644
--- a/compiler/rustc_resolve/src/errors.rs
+++ b/compiler/rustc_resolve/src/errors.rs
@@ -59,7 +59,7 @@ pub(crate) struct NameAlreadyUsedInParameterList {
     pub(crate) span: Span,
     #[label(resolve_first_use_of_name)]
     pub(crate) first_use_span: Span,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -142,7 +142,7 @@ pub(crate) struct VariableBoundWithDifferentMode {
     pub(crate) span: Span,
     #[label(resolve_first_binding_span)]
     pub(crate) first_binding_span: Span,
-    pub(crate) variable_name: Symbol,
+    pub(crate) variable_name: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -151,7 +151,7 @@ pub(crate) struct IdentifierBoundMoreThanOnceInParameterList {
     #[primary_span]
     #[label]
     pub(crate) span: Span,
-    pub(crate) identifier: Symbol,
+    pub(crate) identifier: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -160,7 +160,7 @@ pub(crate) struct IdentifierBoundMoreThanOnceInSamePattern {
     #[primary_span]
     #[label]
     pub(crate) span: Span,
-    pub(crate) identifier: Symbol,
+    pub(crate) identifier: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -478,7 +478,7 @@ pub(crate) struct TraitImplDuplicate {
     pub(crate) old_span: Span,
     #[label(resolve_trait_item_span)]
     pub(crate) trait_item_span: Span,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
 }
 
 #[derive(Diagnostic)]
@@ -976,7 +976,7 @@ pub(crate) struct AttemptToDefineBuiltinMacroTwice {
 pub(crate) struct VariableIsNotBoundInAllPatterns {
     #[primary_span]
     pub(crate) multispan: MultiSpan,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
 }
 
 #[derive(Subdiagnostic, Debug, Clone)]
@@ -984,7 +984,7 @@ pub(crate) struct VariableIsNotBoundInAllPatterns {
 pub(crate) struct PatternDoesntBindName {
     #[primary_span]
     pub(crate) span: Span,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
 }
 
 #[derive(Subdiagnostic, Debug, Clone)]
@@ -1260,7 +1260,7 @@ pub(crate) struct TraitImplMismatch {
     #[primary_span]
     #[label]
     pub(crate) span: Span,
-    pub(crate) name: Symbol,
+    pub(crate) name: Ident,
     pub(crate) kind: &'static str,
     pub(crate) trait_path: String,
     #[label(resolve_trait_impl_mismatch_label_item)]
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 8bd40ed3a73..68d3351f174 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -2835,7 +2835,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 match seen_bindings.entry(ident) {
                     Entry::Occupied(entry) => {
                         let span = *entry.get();
-                        let err = ResolutionError::NameAlreadyUsedInParameterList(ident.name, span);
+                        let err = ResolutionError::NameAlreadyUsedInParameterList(ident, span);
                         self.report_error(param.ident.span, err);
                         let rib = match param.kind {
                             GenericParamKind::Lifetime => {
@@ -3422,7 +3422,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         match seen_trait_items.entry(id_in_trait) {
             Entry::Occupied(entry) => {
                 self.report_error(span, ResolutionError::TraitImplDuplicate {
-                    name: ident.name,
+                    name: ident,
                     old_span: *entry.get(),
                     trait_item_span: binding.span,
                 });
@@ -3457,7 +3457,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
         };
         let trait_path = path_names_to_string(path);
         self.report_error(span, ResolutionError::TraitImplMismatch {
-            name: ident.name,
+            name: ident,
             kind,
             code,
             trait_path,
@@ -3640,9 +3640,8 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 .filter(|(_, pat)| pat.id != pat_outer.id)
                 .flat_map(|(map, _)| map);
 
-            for (key, binding_inner) in inners {
-                let name = key.name;
-                match map_outer.get(key) {
+            for (&name, binding_inner) in inners {
+                match map_outer.get(&name) {
                     None => {
                         // The inner binding is missing in the outer.
                         let binding_error =
@@ -3880,7 +3879,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
                 // `Variant(a, a)`:
                 _ => IdentifierBoundMoreThanOnceInSamePattern,
             };
-            self.report_error(ident.span, error(ident.name));
+            self.report_error(ident.span, error(ident));
         }
 
         // Record as bound if it's valid:
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index 17c92c7b501..2db8087fd83 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -1636,13 +1636,12 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                                         .enumerate()
                                         .map(|(idx, new)| (new, old_fields.get(idx)))
                                         .map(|(new, old)| {
-                                            let new = new.name.to_ident_string();
                                             if let Some(Some(old)) = old
-                                                && new != *old
+                                                && new.as_str() != old
                                             {
                                                 format!("{new}: {old}")
                                             } else {
-                                                new
+                                                new.to_string()
                                             }
                                         })
                                         .collect::<Vec<String>>()
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 3b18e480be4..04144eb616f 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -214,7 +214,7 @@ enum Used {
 
 #[derive(Debug)]
 struct BindingError {
-    name: Symbol,
+    name: Ident,
     origin: BTreeSet<Span>,
     target: BTreeSet<Span>,
     could_be_path: bool,
@@ -226,7 +226,7 @@ enum ResolutionError<'ra> {
     GenericParamsFromOuterItem(Res, HasGenericParams, DefKind),
     /// Error E0403: the name is already used for a type or const parameter in this generic
     /// parameter list.
-    NameAlreadyUsedInParameterList(Symbol, Span),
+    NameAlreadyUsedInParameterList(Ident, Span),
     /// Error E0407: method is not a member of trait.
     MethodNotMemberOfTrait(Ident, String, Option<Symbol>),
     /// Error E0437: type is not a member of trait.
@@ -236,11 +236,11 @@ enum ResolutionError<'ra> {
     /// Error E0408: variable `{}` is not bound in all patterns.
     VariableNotBoundInPattern(BindingError, ParentScope<'ra>),
     /// Error E0409: variable `{}` is bound in inconsistent ways within the same match arm.
-    VariableBoundWithDifferentMode(Symbol, Span),
+    VariableBoundWithDifferentMode(Ident, Span),
     /// Error E0415: identifier is bound more than once in this parameter list.
-    IdentifierBoundMoreThanOnceInParameterList(Symbol),
+    IdentifierBoundMoreThanOnceInParameterList(Ident),
     /// Error E0416: identifier is bound more than once in the same pattern.
-    IdentifierBoundMoreThanOnceInSamePattern(Symbol),
+    IdentifierBoundMoreThanOnceInSamePattern(Ident),
     /// Error E0426: use of undeclared label.
     UndeclaredLabel { name: Symbol, suggestion: Option<LabelSuggestion> },
     /// Error E0429: `self` imports are only allowed within a `{ }` list.
@@ -292,14 +292,14 @@ enum ResolutionError<'ra> {
     UnreachableLabel { name: Symbol, definition_span: Span, suggestion: Option<LabelSuggestion> },
     /// Error E0323, E0324, E0325: mismatch between trait item and impl item.
     TraitImplMismatch {
-        name: Symbol,
+        name: Ident,
         kind: &'static str,
         trait_path: String,
         trait_item_span: Span,
         code: ErrCode,
     },
     /// Error E0201: multiple impl items for the same trait item.
-    TraitImplDuplicate { name: Symbol, trait_item_span: Span, old_span: Span },
+    TraitImplDuplicate { name: Ident, trait_item_span: Span, old_span: Span },
     /// Inline asm `sym` operand must refer to a `fn` or `static`.
     InvalidAsmSym,
     /// `self` used instead of `Self` in a generic parameter
diff --git a/compiler/rustc_target/src/spec/targets/aarch64_unknown_nuttx.rs b/compiler/rustc_target/src/spec/targets/aarch64_unknown_nuttx.rs
index 04fd3ec1c26..582211b02b6 100644
--- a/compiler/rustc_target/src/spec/targets/aarch64_unknown_nuttx.rs
+++ b/compiler/rustc_target/src/spec/targets/aarch64_unknown_nuttx.rs
@@ -36,7 +36,7 @@ pub(crate) fn target() -> Target {
             description: Some("AArch64 NuttX".into()),
             tier: Some(3),
             host_tools: Some(false),
-            std: Some(false),
+            std: Some(true),
         },
         pointer_width: 64,
         data_layout: "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32".into(),
diff --git a/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabi.rs
index 138716e8f14..08cbfc74396 100644
--- a/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabi.rs
@@ -31,7 +31,7 @@ pub(crate) fn target() -> Target {
             description: Some("ARMv7-A Cortex-A with NuttX".into()),
             tier: Some(3),
             host_tools: Some(false),
-            std: Some(false),
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabihf.rs b/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabihf.rs
index 40391c9f48e..f68c11a9c68 100644
--- a/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabihf.rs
+++ b/compiler/rustc_target/src/spec/targets/armv7a_nuttx_eabihf.rs
@@ -31,7 +31,7 @@ pub(crate) fn target() -> Target {
             description: Some("ARMv7-A Cortex-A with NuttX (hard float)".into()),
             tier: Some(3),
             host_tools: Some(false),
-            std: Some(false),
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/riscv32imac_unknown_nuttx_elf.rs b/compiler/rustc_target/src/spec/targets/riscv32imac_unknown_nuttx_elf.rs
index 31c9180c509..3eb3d18faf4 100644
--- a/compiler/rustc_target/src/spec/targets/riscv32imac_unknown_nuttx_elf.rs
+++ b/compiler/rustc_target/src/spec/targets/riscv32imac_unknown_nuttx_elf.rs
@@ -6,9 +6,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "riscv32".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         arch: "riscv32".into(),
diff --git a/compiler/rustc_target/src/spec/targets/riscv32imafc_unknown_nuttx_elf.rs b/compiler/rustc_target/src/spec/targets/riscv32imafc_unknown_nuttx_elf.rs
index 08dd3cc2a09..7864f7f8f9a 100644
--- a/compiler/rustc_target/src/spec/targets/riscv32imafc_unknown_nuttx_elf.rs
+++ b/compiler/rustc_target/src/spec/targets/riscv32imafc_unknown_nuttx_elf.rs
@@ -6,9 +6,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "riscv32".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         arch: "riscv32".into(),
diff --git a/compiler/rustc_target/src/spec/targets/riscv32imc_unknown_nuttx_elf.rs b/compiler/rustc_target/src/spec/targets/riscv32imc_unknown_nuttx_elf.rs
index e86549806dd..60d8ec576af 100644
--- a/compiler/rustc_target/src/spec/targets/riscv32imc_unknown_nuttx_elf.rs
+++ b/compiler/rustc_target/src/spec/targets/riscv32imc_unknown_nuttx_elf.rs
@@ -6,9 +6,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "riscv32".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         arch: "riscv32".into(),
diff --git a/compiler/rustc_target/src/spec/targets/riscv64gc_unknown_nuttx_elf.rs b/compiler/rustc_target/src/spec/targets/riscv64gc_unknown_nuttx_elf.rs
index c389759aecd..2cbb8c19b84 100644
--- a/compiler/rustc_target/src/spec/targets/riscv64gc_unknown_nuttx_elf.rs
+++ b/compiler/rustc_target/src/spec/targets/riscv64gc_unknown_nuttx_elf.rs
@@ -8,9 +8,9 @@ pub(crate) fn target() -> Target {
         data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         llvm_target: "riscv64".into(),
         pointer_width: 64,
diff --git a/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs b/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs
index 9c181665581..306b23d2787 100644
--- a/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs
+++ b/compiler/rustc_target/src/spec/targets/riscv64imac_unknown_nuttx_elf.rs
@@ -8,9 +8,9 @@ pub(crate) fn target() -> Target {
         data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         llvm_target: "riscv64".into(),
         pointer_width: 64,
diff --git a/compiler/rustc_target/src/spec/targets/thumbv6m_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv6m_nuttx_eabi.rs
index 5799bbf551f..dcf98acc41f 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv6m_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv6m_nuttx_eabi.rs
@@ -7,9 +7,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv6m-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
@@ -22,12 +22,9 @@ pub(crate) fn target() -> Target {
             llvm_floatabi: Some(FloatAbi::Soft),
             // The ARMv6-M architecture doesn't support unaligned loads/stores so we disable them
             // with +strict-align.
-            // Also force-enable 32-bit atomics, which allows the use of atomic load/store only.
-            // The resulting atomics are ABI incompatible with atomics backed by libatomic.
-            features: "+strict-align,+atomics-32".into(),
-            // There are no atomic CAS instructions available in the instruction set of the ARMv6-M
-            // architecture
-            atomic_cas: false,
+            // The ARMv6-M doesn't support hardware atomic operations, use atomic builtins instead.
+            features: "+strict-align".into(),
+            max_atomic_width: Some(32),
             ..base::thumb::opts()
         },
     }
diff --git a/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabi.rs
index 7fd22602e56..b5cb393f4b0 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabi.rs
@@ -11,9 +11,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv7a-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabihf.rs b/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabihf.rs
index d3148c53a82..1aa44a8cc93 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabihf.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv7a_nuttx_eabihf.rs
@@ -14,9 +14,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv7a-none-eabihf".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabi.rs
index 536d128590f..a3bc4013e53 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabi.rs
@@ -16,9 +16,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv7em-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabihf.rs b/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabihf.rs
index 35e92b81d87..14bbe38257d 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabihf.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv7em_nuttx_eabihf.rs
@@ -15,9 +15,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv7em-none-eabihf".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv7m_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv7m_nuttx_eabi.rs
index 320867444ad..2a77f48a9cd 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv7m_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv7m_nuttx_eabi.rs
@@ -7,9 +7,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv7m-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv8m_base_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv8m_base_nuttx_eabi.rs
index 1af01b97666..25a100e9c7e 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv8m_base_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv8m_base_nuttx_eabi.rs
@@ -7,9 +7,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv8m.base-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabi.rs b/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabi.rs
index 661d74217ad..0bfe2b32ad4 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabi.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabi.rs
@@ -8,9 +8,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv8m.main-none-eabi".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabihf.rs b/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabihf.rs
index 484d35bfc20..9f75f23aa93 100644
--- a/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabihf.rs
+++ b/compiler/rustc_target/src/spec/targets/thumbv8m_main_nuttx_eabihf.rs
@@ -8,9 +8,9 @@ pub(crate) fn target() -> Target {
         llvm_target: "thumbv8m.main-none-eabihf".into(),
         metadata: crate::spec::TargetMetadata {
             description: None,
-            tier: None,
+            tier: Some(3),
             host_tools: None,
-            std: None,
+            std: Some(true),
         },
         pointer_width: 32,
         data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index 961719f263c..5021fd8bf83 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -462,6 +462,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                             err.note(
                                 "`#[target_feature]` functions do not implement the `Fn` traits",
                             );
+                            err.note(
+                                "try casting the function to a `fn` pointer or wrapping it in a closure",
+                            );
                         }
 
                         self.try_to_add_help_message(
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/on_unimplemented.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/on_unimplemented.rs
index 2d932e36470..4e0b097db4c 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/on_unimplemented.rs
@@ -13,7 +13,7 @@ use rustc_middle::ty::print::PrintTraitRefExt as _;
 use rustc_middle::ty::{self, GenericArgsRef, GenericParamDefKind, TyCtxt};
 use rustc_parse_format::{ParseMode, Parser, Piece, Position};
 use rustc_session::lint::builtin::UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES;
-use rustc_span::{Span, Symbol, kw, sym};
+use rustc_span::{Ident, Span, Symbol, kw, sym};
 use tracing::{debug, info};
 use {rustc_attr_parsing as attr, rustc_hir as hir};
 
@@ -375,7 +375,7 @@ impl IgnoredDiagnosticOption {
 #[help]
 pub struct UnknownFormatParameterForOnUnimplementedAttr {
     argument_name: Symbol,
-    trait_name: Symbol,
+    trait_name: Ident,
 }
 
 #[derive(LintDiagnostic)]
@@ -792,7 +792,7 @@ impl<'tcx> OnUnimplementedFormatString {
             tcx.trait_id_of_impl(item_def_id)
                 .expect("expected `on_unimplemented` to correspond to a trait")
         };
-        let trait_name = tcx.item_name(trait_def_id);
+        let trait_name = tcx.item_ident(trait_def_id);
         let generics = tcx.generics_of(item_def_id);
         let s = self.symbol.as_str();
         let mut parser = Parser::new(s, None, None, false, ParseMode::Format);
@@ -821,7 +821,11 @@ impl<'tcx> OnUnimplementedFormatString {
                         Position::ArgumentNamed(s) => {
                             match Symbol::intern(s) {
                                 // `{ThisTraitsName}` is allowed
-                                s if s == trait_name && !self.is_diagnostic_namespace_variant => (),
+                                s if s == trait_name.name
+                                    && !self.is_diagnostic_namespace_variant =>
+                                {
+                                    ()
+                                }
                                 s if ALLOWED_FORMAT_SYMBOLS.contains(&s)
                                     && !self.is_diagnostic_namespace_variant =>
                                 {