Auto merge of #62635 - Centril:rollup-potvfnk, r=Centril

Rollup of 12 pull requests

Successful merges:

 - #61535 (Coherence test when a generic type param has a default value from an associated type)
 - #62274 (rustc_mir: follow FalseUnwind's real_target edge in qualify_consts.)
 - #62431 (Add messages to `Option`'s and `Result`'s `must_use` annotation for `is_*`)
 - #62453 (in which we suggest anonymizing single-use lifetimes in paths )
 - #62568 (Replace unsafe_destructor_blind_to_params with may_dangle)
 - #62578 (Add test for #49919)
 - #62595 (Document that the crate keyword refers to the project root)
 - #62599 (move mem::uninitialized deprecation back by 1 release, to 1.39)
 - #62605 (Emit dropped unemitted errors to aid in ICE debugging)
 - #62607 (Correctly break out of recovery loop)
 - #62608 (`async unsafe fn` tests)
 - #62623 (downgrade indirect_structural_match lint to allow)

Failed merges:

r? @ghost

69 files changed, 502 insertions, 241 deletions

diff --git a/RELEASES.md b/RELEASES.md
index 5ceeea8d037..355e53cbed2 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -62,7 +62,7 @@ Misc
 Compatibility Notes
 -------------------
 - With the stabilisation of `mem::MaybeUninit`, `mem::uninitialized` use is no
-  longer recommended, and will be deprecated in 1.38.0.
+  longer recommended, and will be deprecated in 1.39.0.
 
 [60318]: https://github.com/rust-lang/rust/pull/60318/
 [60364]: https://github.com/rust-lang/rust/pull/60364/
diff --git a/src/libcore/mem/mod.rs b/src/libcore/mem/mod.rs
index b62d81affdd..f2729168763 100644
--- a/src/libcore/mem/mod.rs
+++ b/src/libcore/mem/mod.rs
@@ -472,7 +472,7 @@ pub unsafe fn zeroed<T>() -> T {
 /// [`MaybeUninit<T>`]: union.MaybeUninit.html
 /// [inv]: union.MaybeUninit.html#initialization-invariant
 #[inline]
-#[rustc_deprecated(since = "1.38.0", reason = "use `mem::MaybeUninit` instead")]
+#[rustc_deprecated(since = "1.39.0", reason = "use `mem::MaybeUninit` instead")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub unsafe fn uninitialized<T>() -> T {
     MaybeUninit::uninit().assume_init()
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 29169951e46..193cdb15b54 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -178,7 +178,7 @@ impl<T> Option<T> {
     /// ```
     ///
     /// [`Some`]: #variant.Some
-    #[must_use]
+    #[must_use = "if you intended to assert that this has a value, consider `.unwrap()` instead"]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn is_some(&self) -> bool {
@@ -201,7 +201,8 @@ impl<T> Option<T> {
     /// ```
     ///
     /// [`None`]: #variant.None
-    #[must_use]
+    #[must_use = "if you intended to assert that this doesn't have a value, consider \
+                  `.and_then(|| panic!(\"`Option` had a value when expected `None`\"))` instead"]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn is_none(&self) -> bool {
diff --git a/src/libcore/result.rs b/src/libcore/result.rs
index b64ad149cf4..ba72e1e75f8 100644
--- a/src/libcore/result.rs
+++ b/src/libcore/result.rs
@@ -277,7 +277,7 @@ impl<T, E> Result<T, E> {
     /// let x: Result<i32, &str> = Err("Some error message");
     /// assert_eq!(x.is_ok(), false);
     /// ```
-    #[must_use]
+    #[must_use = "if you intended to assert that this is ok, consider `.unwrap()` instead"]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn is_ok(&self) -> bool {
@@ -302,7 +302,7 @@ impl<T, E> Result<T, E> {
     /// let x: Result<i32, &str> = Err("Some error message");
     /// assert_eq!(x.is_err(), true);
     /// ```
-    #[must_use]
+    #[must_use = "if you intended to assert that this is err, consider `.unwrap_err()` instead"]
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn is_err(&self) -> bool {
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 9b4b97202d9..d1cae76de60 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -350,7 +350,8 @@ declare_lint! {
 
 declare_lint! {
     pub INDIRECT_STRUCTURAL_MATCH,
-    Warn,
+    // defaulting to allow until rust-lang/rust#62614 is fixed.
+    Allow,
     "pattern with const indirectly referencing non-`#[structural_match]` type"
 }
 
@@ -451,6 +452,7 @@ declare_lint_pass! {
         AMBIGUOUS_ASSOCIATED_ITEMS,
         NESTED_IMPL_TRAIT,
         MUTABLE_BORROW_RESERVATION_CONFLICT,
+        INDIRECT_STRUCTURAL_MATCH,
     ]
 }
 
diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index 3221b41ee1d..beb8061842d 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -9,7 +9,7 @@ use crate::hir::def::{Res, DefKind};
 use crate::hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE};
 use crate::hir::map::Map;
 use crate::hir::ptr::P;
-use crate::hir::{GenericArg, GenericParam, ItemLocalId, LifetimeName, Node, ParamName};
+use crate::hir::{GenericArg, GenericParam, ItemLocalId, LifetimeName, Node, ParamName, QPath};
 use crate::ty::{self, DefIdTree, GenericParamDefKind, TyCtxt};
 
 use crate::rustc::lint;
@@ -1458,10 +1458,10 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
     }
 
     // helper method to issue suggestions from `fn rah<'a>(&'a T)` to `fn rah(&T)`
+    // or from `fn rah<'a>(T<'a>)` to `fn rah(T<'_>)`
     fn suggest_eliding_single_use_lifetime(
         &self, err: &mut DiagnosticBuilder<'_>, def_id: DefId, lifetime: &hir::Lifetime
     ) {
-        // FIXME: future work: also suggest `impl Foo<'_>` for `impl<'a> Foo<'a>`
         let name = lifetime.name.ident();
         let mut remove_decl = None;
         if let Some(parent_def_id) = self.tcx.parent(def_id) {
@@ -1471,18 +1471,38 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         }
 
         let mut remove_use = None;
+        let mut elide_use = None;
         let mut find_arg_use_span = |inputs: &hir::HirVec<hir::Ty>| {
             for input in inputs {
-                if let hir::TyKind::Rptr(lt, _) = input.node {
-                    if lt.name.ident() == name {
-                        // include the trailing whitespace between the ampersand and the type name
-                        let lt_through_ty_span = lifetime.span.to(input.span.shrink_to_hi());
-                        remove_use = Some(
-                            self.tcx.sess.source_map()
-                                .span_until_non_whitespace(lt_through_ty_span)
-                        );
-                        break;
+                match input.node {
+                    hir::TyKind::Rptr(lt, _) => {
+                        if lt.name.ident() == name {
+                            // include the trailing whitespace between the lifetime and type names
+                            let lt_through_ty_span = lifetime.span.to(input.span.shrink_to_hi());
+                            remove_use = Some(
+                                self.tcx.sess.source_map()
+                                    .span_until_non_whitespace(lt_through_ty_span)
+                            );
+                            break;
+                        }
                     }
+                    hir::TyKind::Path(ref qpath) => {
+                        if let QPath::Resolved(_, path) = qpath {
+
+                            let last_segment = &path.segments[path.segments.len()-1];
+                            let generics = last_segment.generic_args();
+                            for arg in generics.args.iter() {
+                                if let GenericArg::Lifetime(lt) = arg {
+                                    if lt.name.ident() == name {
+                                        elide_use = Some(lt.span);
+                                        break;
+                                    }
+                                }
+                            }
+                            break;
+                        }
+                    },
+                    _ => {}
                 }
             }
         };
@@ -1506,24 +1526,35 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
             }
         }
 
-        if let (Some(decl_span), Some(use_span)) = (remove_decl, remove_use) {
-            // if both declaration and use deletion spans start at the same
-            // place ("start at" because the latter includes trailing
-            // whitespace), then this is an in-band lifetime
-            if decl_span.shrink_to_lo() == use_span.shrink_to_lo() {
-                err.span_suggestion(
-                    use_span,
-                    "elide the single-use lifetime",
-                    String::new(),
-                    Applicability::MachineApplicable,
-                );
-            } else {
+        let msg = "elide the single-use lifetime";
+        match (remove_decl, remove_use, elide_use) {
+            (Some(decl_span), Some(use_span), None) => {
+                // if both declaration and use deletion spans start at the same
+                // place ("start at" because the latter includes trailing
+                // whitespace), then this is an in-band lifetime
+                if decl_span.shrink_to_lo() == use_span.shrink_to_lo() {
+                    err.span_suggestion(
+                        use_span,
+                        msg,
+                        String::new(),
+                        Applicability::MachineApplicable,
+                    );
+                } else {
+                    err.multipart_suggestion(
+                        msg,
+                        vec![(decl_span, String::new()), (use_span, String::new())],
+                        Applicability::MachineApplicable,
+                    );
+                }
+            }
+            (Some(decl_span), None, Some(use_span)) => {
                 err.multipart_suggestion(
-                    "elide the single-use lifetime",
-                    vec![(decl_span, String::new()), (use_span, String::new())],
+                    msg,
+                    vec![(decl_span, String::new()), (use_span, "'_".to_owned())],
                     Applicability::MachineApplicable,
                 );
             }
+            _ => {}
         }
     }
 
diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index a3b99f143d0..56cb89b5144 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -22,7 +22,6 @@ use rustc_macros::HashStable;
 use std::{cmp, fmt};
 use syntax::ast;
 use syntax::attr::{self, SignedInt, UnsignedInt};
-use syntax::symbol::sym;
 use syntax_pos::{Span, DUMMY_SP};
 
 #[derive(Copy, Clone, Debug)]
@@ -435,20 +434,6 @@ impl<'tcx> TyCtxt<'tcx> {
             Some(dtor) => dtor.did
         };
 
-        // RFC 1238: if the destructor method is tagged with the
-        // attribute `unsafe_destructor_blind_to_params`, then the
-        // compiler is being instructed to *assume* that the
-        // destructor will not access borrowed data,
-        // even if such data is otherwise reachable.
-        //
-        // Such access can be in plain sight (e.g., dereferencing
-        // `*foo.0` of `Foo<'a>(&'a u32)`) or indirectly hidden
-        // (e.g., calling `foo.0.clone()` of `Foo<T:Clone>`).
-        if self.has_attr(dtor, sym::unsafe_destructor_blind_to_params) {
-            debug!("destructor_constraint({:?}) - blind", def.did);
-            return vec![];
-        }
-
         let impl_def_id = self.associated_item(dtor).container.id();
         let impl_generics = self.generics_of(impl_def_id);
 
diff --git a/src/librustc_errors/diagnostic_builder.rs b/src/librustc_errors/diagnostic_builder.rs
index fc74e43ff57..41d0638f7c6 100644
--- a/src/librustc_errors/diagnostic_builder.rs
+++ b/src/librustc_errors/diagnostic_builder.rs
@@ -380,10 +380,13 @@ impl<'a> Debug for DiagnosticBuilder<'a> {
 impl<'a> Drop for DiagnosticBuilder<'a> {
     fn drop(&mut self) {
         if !panicking() && !self.cancelled() {
-            let mut db = DiagnosticBuilder::new(self.handler,
-                                                Level::Bug,
-                                                "Error constructed but not emitted");
+            let mut db = DiagnosticBuilder::new(
+                self.handler,
+                Level::Bug,
+                "the following error was constructed but not emitted",
+            );
             db.emit();
+            self.emit();
             panic!();
         }
     }
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index 1fa539f8a2a..21b8f06d089 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -890,6 +890,7 @@ impl<'a, 'tcx> Checker<'a, 'tcx> {
 
             let target = match body[bb].terminator().kind {
                 TerminatorKind::Goto { target } |
+                TerminatorKind::FalseUnwind { real_target: target, .. } |
                 TerminatorKind::Drop { target, .. } |
                 TerminatorKind::DropAndReplace { target, .. } |
                 TerminatorKind::Assert { target, .. } |
@@ -908,8 +909,7 @@ impl<'a, 'tcx> Checker<'a, 'tcx> {
                 TerminatorKind::GeneratorDrop |
                 TerminatorKind::Yield { .. } |
                 TerminatorKind::Unreachable |
-                TerminatorKind::FalseEdges { .. } |
-                TerminatorKind::FalseUnwind { .. } => None,
+                TerminatorKind::FalseEdges { .. } => None,
 
                 TerminatorKind::Return => {
                     break;
diff --git a/src/librustc_typeck/check/dropck.rs b/src/librustc_typeck/check/dropck.rs
index c4c4e10a14c..babffe479bc 100644
--- a/src/librustc_typeck/check/dropck.rs
+++ b/src/librustc_typeck/check/dropck.rs
@@ -246,7 +246,7 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
 ///
 /// * (1.) `D` has a lifetime- or type-parametric Drop implementation,
 ///        (where that `Drop` implementation does not opt-out of
-///         this check via the `unsafe_destructor_blind_to_params`
+///         this check via the `may_dangle`
 ///         attribute), and
 /// * (2.) the structure of `D` can reach a reference of type `&'a _`,
 ///
@@ -279,7 +279,7 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
 /// instead Drop-Check now simply assumes that if a destructor has
 /// access (direct or indirect) to a lifetime parameter, then that
 /// lifetime must be forced to outlive that destructor's dynamic
-/// extent. We then provide the `unsafe_destructor_blind_to_params`
+/// extent. We then provide the `may_dangle`
 /// attribute as a way for destructor implementations to opt-out of
 /// this conservative assumption (and thus assume the obligation of
 /// ensuring that they do not access data nor invoke methods of
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index 5c6847b4141..3cd520fd4b5 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -3809,7 +3809,6 @@ const ATTRIBUTE_WHITELIST: &'static [Symbol] = &[
     sym::must_use,
     sym::no_mangle,
     sym::repr,
-    sym::unsafe_destructor_blind_to_params,
     sym::non_exhaustive
 ];
 
diff --git a/src/libstd/keyword_docs.rs b/src/libstd/keyword_docs.rs
index d18fcb4a1da..f5018485ef7 100644
--- a/src/libstd/keyword_docs.rs
+++ b/src/libstd/keyword_docs.rs
@@ -119,7 +119,7 @@ mod continue_keyword { }
 /// The `as` keyword can be used to change what the crate is referred to as in your project. If a
 /// crate name includes a dash, it is implicitly imported with the dashes replaced by underscores.
 ///
-/// `crate` is also used as in conjunction with `pub` to signify that the item it's attached to
+/// `crate` can also be used as in conjunction with `pub` to signify that the item it's attached to
 /// is public only to other members of the same crate it's in.
 ///
 /// ```rust
@@ -131,6 +131,10 @@ mod continue_keyword { }
 /// }
 /// ```
 ///
+/// `crate` is also used to represent the absolute path of a module, where `crate` refers to the
+/// root of the current crate. For instance, `crate::foo::bar` refers to the name `bar` inside the
+/// module `foo`, from anywhere else in the same crate.
+///
 /// [Reference]: ../reference/items/extern-crates.html
 mod crate_keyword { }
 
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 84a012f03c9..e3628d908fb 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -199,9 +199,6 @@ declare_features! (
 
     // no-tracking-issue-end
 
-    // Allows using `#[unsafe_destructor_blind_to_params]` (RFC 1238).
-    (active, dropck_parametricity, "1.3.0", Some(28498), None),
-
     // no-tracking-issue-start
 
     // Allows using `#[omit_gdb_pretty_printer_section]`.
@@ -641,6 +638,8 @@ declare_features! (
     (removed, extern_in_paths, "1.33.0", Some(55600), None,
      Some("subsumed by `::foo::bar` paths")),
     (removed, quote, "1.33.0", Some(29601), None, None),
+    // Allows using `#[unsafe_destructor_blind_to_params]` (RFC 1238).
+    (removed, dropck_parametricity, "1.38.0", Some(28498), None, None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: removed features
@@ -1447,15 +1446,6 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
             cfg_fn!(omit_gdb_pretty_printer_section)
         )
     ),
-    (sym::unsafe_destructor_blind_to_params,
-    Normal,
-    template!(Word),
-    Gated(Stability::Deprecated("https://github.com/rust-lang/rust/issues/34761",
-                                Some("replace this attribute with `#[may_dangle]`")),
-        sym::dropck_parametricity,
-        "unsafe_destructor_blind_to_params has been replaced by \
-            may_dangle and will be removed in the future",
-        cfg_fn!(dropck_parametricity))),
     (sym::may_dangle,
     Normal,
     template!(Word),
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 83dbff6b2d5..e0633f73ac4 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4629,6 +4629,9 @@ impl<'a> Parser<'a> {
     fn parse_block_tail(&mut self, lo: Span, s: BlockCheckMode) -> PResult<'a, P<Block>> {
         let mut stmts = vec![];
         while !self.eat(&token::CloseDelim(token::Brace)) {
+            if self.token == token::Eof {
+                break;
+            }
             let stmt = match self.parse_full_stmt(false) {
                 Err(mut err) => {
                     err.emit();
@@ -4643,8 +4646,6 @@ impl<'a> Parser<'a> {
             };
             if let Some(stmt) = stmt {
                 stmts.push(stmt);
-            } else if self.token == token::Eof {
-                break;
             } else {
                 // Found only `;` or `}`.
                 continue;
@@ -6666,12 +6667,13 @@ impl<'a> Parser<'a> {
     }
 
     /// Reads a module from a source file.
-    fn eval_src_mod(&mut self,
-                    path: PathBuf,
-                    directory_ownership: DirectoryOwnership,
-                    name: String,
-                    id_sp: Span)
-                    -> PResult<'a, (ast::Mod, Vec<Attribute> )> {
+    fn eval_src_mod(
+        &mut self,
+        path: PathBuf,
+        directory_ownership: DirectoryOwnership,
+        name: String,
+        id_sp: Span,
+    ) -> PResult<'a, (ast::Mod, Vec<Attribute>)> {
         let mut included_mod_stack = self.sess.included_mod_stack.borrow_mut();
         if let Some(i) = included_mod_stack.iter().position(|p| *p == path) {
             let mut err = String::from("circular modules: ");
diff --git a/src/libsyntax/util/parser_testing.rs b/src/libsyntax/util/parser_testing.rs
index f850960624c..2ef32d37d44 100644
--- a/src/libsyntax/util/parser_testing.rs
+++ b/src/libsyntax/util/parser_testing.rs
@@ -34,7 +34,7 @@ fn with_error_checking_parse<'a, T, F>(s: String, ps: &'a ParseSess, f: F) -> T
 }
 
 /// Parse a string, return a crate.
-pub fn string_to_crate (source_str : String) -> ast::Crate {
+pub fn string_to_crate(source_str : String) -> ast::Crate {
     let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_crate_mod()
@@ -42,7 +42,7 @@ pub fn string_to_crate (source_str : String) -> ast::Crate {
 }
 
 /// Parse a string, return an expr
-pub fn string_to_expr (source_str : String) -> P<ast::Expr> {
+pub fn string_to_expr(source_str : String) -> P<ast::Expr> {
     let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_expr()
@@ -50,7 +50,7 @@ pub fn string_to_expr (source_str : String) -> P<ast::Expr> {
 }
 
 /// Parse a string, return an item
-pub fn string_to_item (source_str : String) -> Option<P<ast::Item>> {
+pub fn string_to_item(source_str : String) -> Option<P<ast::Item>> {
     let ps = ParseSess::new(FilePathMapping::empty());
     with_error_checking_parse(source_str, &ps, |p| {
         p.parse_item()
diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 581fd47c4b3..a983180ac01 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -695,7 +695,6 @@ symbols! {
         unmarked_api,
         unreachable_code,
         unrestricted_attribute_tokens,
-        unsafe_destructor_blind_to_params,
         unsafe_no_drop_flag,
         unsized_locals,
         unsized_tuple_coercion,
diff --git a/src/test/compile-fail/const-fn-error.rs b/src/test/compile-fail/const-fn-error.rs
index 87a9cf9490d..1de23f2a5e9 100644
--- a/src/test/compile-fail/const-fn-error.rs
+++ b/src/test/compile-fail/const-fn-error.rs
@@ -6,6 +6,7 @@ const fn f(x: usize) -> usize {
     let mut sum = 0;
     for i in 0..x {
         //~^ ERROR E0015
+        //~| ERROR E0017
         //~| ERROR E0019
         //~| ERROR E0019
         //~| ERROR E0080
diff --git a/src/test/compile-fail/issue-52443.rs b/src/test/compile-fail/issue-52443.rs
index a993d811d32..28d9937b5e8 100644
--- a/src/test/compile-fail/issue-52443.rs
+++ b/src/test/compile-fail/issue-52443.rs
@@ -1,10 +1,14 @@
 fn main() {
     [(); & { loop { continue } } ]; //~ ERROR mismatched types
     [(); loop { break }]; //~ ERROR mismatched types
-    [(); {while true {break}; 0}]; //~ ERROR constant contains unimplemented expression type
-    //~^ WARN denote infinite loops with
-    [(); { for _ in 0usize.. {}; 0}]; //~ ERROR calls in constants are limited to constant functions
+    [(); {while true {break}; 0}];
     //~^ ERROR constant contains unimplemented expression type
     //~| ERROR constant contains unimplemented expression type
+    //~| WARN denote infinite loops with
+    [(); { for _ in 0usize.. {}; 0}];
+    //~^ ERROR calls in constants are limited to constant functions
+    //~| ERROR references in constants may only refer to immutable values
+    //~| ERROR constant contains unimplemented expression type
+    //~| ERROR constant contains unimplemented expression type
     //~| ERROR evaluation of constant value failed
 }
diff --git a/src/test/run-pass/coherence/auxiliary/re_rebalance_coherence_lib.rs b/src/test/run-pass/coherence/auxiliary/re_rebalance_coherence_lib.rs
index 41b9d64d5f7..9a191bad8b0 100644
--- a/src/test/run-pass/coherence/auxiliary/re_rebalance_coherence_lib.rs
+++ b/src/test/run-pass/coherence/auxiliary/re_rebalance_coherence_lib.rs
@@ -20,3 +20,12 @@ pub struct BatchInsert<'a, T: 'a, Tab> {
 impl<'a, T:'a, Tab, DB> QueryFragment<DB> for BatchInsert<'a, T, Tab>
 where DB: SupportsDefaultKeyword + Backend,
 {}
+
+pub trait LibToOwned {
+    type Owned;
+}
+
+pub struct LibCow<T: LibToOwned, Owned = <T as LibToOwned>::Owned> {
+    pub t: T,
+    pub o: Owned,
+}
diff --git a/src/test/run-pass/coherence/re-rebalance-coherence-default-generic-associated-type.rs b/src/test/run-pass/coherence/re-rebalance-coherence-default-generic-associated-type.rs
new file mode 100644
index 00000000000..4168b7a6146
--- /dev/null
+++ b/src/test/run-pass/coherence/re-rebalance-coherence-default-generic-associated-type.rs
@@ -0,0 +1,27 @@
+// run-pass
+// aux-build:re_rebalance_coherence_lib.rs
+
+#![allow(dead_code)]
+#![feature(re_rebalance_coherence)]
+// check that a generic type with a default value from an associated type can be used without
+// specifying the value, and without invoking coherence errors.
+
+extern crate re_rebalance_coherence_lib as lib;
+use lib::*;
+
+struct MyString {}
+
+impl LibToOwned for MyString {
+    type Owned = String;
+}
+
+impl PartialEq<MyString> for LibCow<MyString> {
+    fn eq(&self, _other: &MyString) -> bool {
+        // Test that the default type is used.
+        let _s: &String = &self.o;
+
+        false
+    }
+}
+
+fn main() {}
diff --git a/src/test/run-pass/issues/issue-24805-dropck-itemless.rs b/src/test/run-pass/issues/issue-24805-dropck-itemless.rs
index db427ed3d31..555eefeb3a1 100644
--- a/src/test/run-pass/issues/issue-24805-dropck-itemless.rs
+++ b/src/test/run-pass/issues/issue-24805-dropck-itemless.rs
@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)]
 
 // Check that item-less traits do not cause dropck to inject extra
 // region constraints.
 
 #![allow(non_camel_case_types)]
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 trait UserDefined { }
 
@@ -20,9 +19,8 @@ impl<'a, T> UserDefined for &'a T { }
 //   ```
 macro_rules! impl_drop {
     ($Bound:ident, $Id:ident) => {
-        struct $Id<T:$Bound>(T);
-        impl <T:$Bound> Drop for $Id<T> {
-            #[unsafe_destructor_blind_to_params]
+        struct $Id<T: $Bound>(T);
+        unsafe impl <#[may_dangle] T: $Bound> Drop for $Id<T> {
             fn drop(&mut self) { }
         }
     }
diff --git a/src/test/run-pass/issues/issue-28498-ugeh-ex1.rs b/src/test/run-pass/issues/issue-28498-ugeh-ex1.rs
index c4f249c45f1..90cf2cddcf0 100644
--- a/src/test/run-pass/issues/issue-28498-ugeh-ex1.rs
+++ b/src/test/run-pass/issues/issue-28498-ugeh-ex1.rs
@@ -1,21 +1,19 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Example taken from RFC 1238 text
 
 // https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md
 //     #example-of-the-unguarded-escape-hatch
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 use std::cell::Cell;
 
 struct Concrete<'a>(u32, Cell<Option<&'a Concrete<'a>>>);
 
 struct Foo<T> { data: Vec<T> }
 
-impl<T> Drop for Foo<T> {
-    // Below is the UGEH attribute
-    #[unsafe_destructor_blind_to_params]
+// Below is the UGEH attribute
+unsafe impl<#[may_dangle] T> Drop for Foo<T> {
     fn drop(&mut self) { }
 }
 
diff --git a/src/test/run-pass/issues/issue-28498-ugeh-with-lifetime-param.rs b/src/test/run-pass/issues/issue-28498-ugeh-with-lifetime-param.rs
index 573ec8f6131..aea9fde5309 100644
--- a/src/test/run-pass/issues/issue-28498-ugeh-with-lifetime-param.rs
+++ b/src/test/run-pass/issues/issue-28498-ugeh-with-lifetime-param.rs
@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a lifetime param
 // to assert that destructor will not access any dead data.
 //
 // Compare with compile-fail/issue28498-reject-lifetime-param.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 #[derive(Debug)]
 struct ScribbleOnDrop(String);
@@ -19,11 +18,9 @@ impl Drop for ScribbleOnDrop {
 
 struct Foo<'a>(u32, &'a ScribbleOnDrop);
 
-impl<'a> Drop for Foo<'a> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] 'a> Drop for Foo<'a> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
-        // because destructor never accesses `self.1`.
+        // Use of `may_dangle` is sound, because destructor never accesses `self.1`.
         println!("Dropping Foo({}, _)", self.0);
     }
 }
diff --git a/src/test/run-pass/issues/issue-28498-ugeh-with-passed-to-fn.rs b/src/test/run-pass/issues/issue-28498-ugeh-with-passed-to-fn.rs
index e0863fa9947..91ef5a7c98d 100644
--- a/src/test/run-pass/issues/issue-28498-ugeh-with-passed-to-fn.rs
+++ b/src/test/run-pass/issues/issue-28498-ugeh-with-passed-to-fn.rs
@@ -1,5 +1,4 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a type param in negative position
 // to assert that destructor will not access any dead data.
@@ -11,7 +10,7 @@
 //
 // Compare with run-pass/issue28498-ugeh-with-passed-to-fn.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 #[derive(Debug)]
 struct ScribbleOnDrop(String);
@@ -24,12 +23,10 @@ impl Drop for ScribbleOnDrop {
 
 struct Foo<T>(u32, T, Box<for <'r> fn(&'r T) -> String>);
 
-impl<T> Drop for Foo<T> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] T> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
-        // because destructor never passes a `self.1` to the callback
-        // (in `self.2`) despite having it available.
+        // Use of `may_dangle` is sound, because destructor never passes a `self.1`
+        // to the callback (in `self.2`) despite having it available.
         println!("Dropping Foo({}, _)", self.0);
     }
 }
diff --git a/src/test/run-pass/issues/issue-28498-ugeh-with-trait-bound.rs b/src/test/run-pass/issues/issue-28498-ugeh-with-trait-bound.rs
index 01d884584f6..808f3b6e81e 100644
--- a/src/test/run-pass/issues/issue-28498-ugeh-with-trait-bound.rs
+++ b/src/test/run-pass/issues/issue-28498-ugeh-with-trait-bound.rs
@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a trait bound
 // to assert that destructor will not access any dead data.
 //
 // Compare with compile-fail/issue28498-reject-trait-bound.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 use std::fmt;
 
@@ -19,14 +18,12 @@ impl Drop for ScribbleOnDrop {
     }
 }
 
-struct Foo<T:fmt::Debug>(u32, T);
+struct Foo<T: fmt::Debug>(u32, T);
 
-impl<T:fmt::Debug> Drop for Foo<T> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] T: fmt::Debug> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
-        // because destructor never accesses the `Debug::fmt` method
-        // of `T`, despite having it available.
+        // Use of `may_dangle` is sound, because destructor never accesses
+        // the `Debug::fmt` method of `T`, despite having it available.
         println!("Dropping Foo({}, _)", self.0);
     }
 }
diff --git a/src/test/ui/async-await/async-await.rs b/src/test/ui/async-await/async-await.rs
index 29622c9d030..5ec99c5d183 100644
--- a/src/test/ui/async-await/async-await.rs
+++ b/src/test/ui/async-await/async-await.rs
@@ -70,6 +70,8 @@ fn async_nonmove_block(x: u8) -> impl Future<Output = u8> {
     }
 }
 
+// see async-closure.rs for async_closure + async_closure_in_unsafe_block
+
 async fn async_fn(x: u8) -> u8 {
     wake_and_yield_once().await;
     x
@@ -120,6 +122,18 @@ async unsafe fn unsafe_async_fn(x: u8) -> u8 {
     x
 }
 
+unsafe fn unsafe_fn(x: u8) -> u8 {
+    x
+}
+
+fn async_block_in_unsafe_block(x: u8) -> impl Future<Output = u8> {
+    unsafe {
+        async move {
+            unsafe_fn(unsafe_async_fn(x).await)
+        }
+    }
+}
+
 struct Foo;
 
 trait Bar {
@@ -176,6 +190,7 @@ fn main() {
         async_fn,
         generic_async_fn,
         async_fn_with_internal_borrow,
+        async_block_in_unsafe_block,
         Foo::async_assoc_item,
         |x| {
             async move {
diff --git a/src/test/ui/async-await/async-closure.rs b/src/test/ui/async-await/async-closure.rs
index f5dc9e24d2d..925b54b3985 100644
--- a/src/test/ui/async-await/async-closure.rs
+++ b/src/test/ui/async-await/async-closure.rs
@@ -53,6 +53,21 @@ fn async_closure(x: u8) -> impl Future<Output = u8> {
     })(x)
 }
 
+fn async_closure_in_unsafe_block(x: u8) -> impl Future<Output = u8> {
+    (unsafe {
+        async move |x: u8| unsafe_fn(unsafe_async_fn(x).await)
+    })(x)
+}
+
+async unsafe fn unsafe_async_fn(x: u8) -> u8 {
+    wake_and_yield_once().await;
+    x
+}
+
+unsafe fn unsafe_fn(x: u8) -> u8 {
+    x
+}
+
 fn test_future_yields_once_then_returns<F, Fut>(f: F)
 where
     F: FnOnce(u8) -> Fut,
@@ -77,5 +92,6 @@ fn main() {
 
     test! {
         async_closure,
+        async_closure_in_unsafe_block,
     }
 }
diff --git a/src/test/ui/async-await/async-unsafe-fn-call-in-safe.rs b/src/test/ui/async-await/async-unsafe-fn-call-in-safe.rs
new file mode 100644
index 00000000000..cb9156dcc6e
--- /dev/null
+++ b/src/test/ui/async-await/async-unsafe-fn-call-in-safe.rs
@@ -0,0 +1,21 @@
+// edition:2018
+
+#![feature(async_await)]
+
+struct S;
+
+impl S {
+    async unsafe fn f() {}
+}
+
+async unsafe fn f() {}
+
+async fn g() {
+    S::f(); //~ ERROR call to unsafe function is unsafe
+    f(); //~ ERROR call to unsafe function is unsafe
+}
+
+fn main() {
+    S::f(); //~ ERROR call to unsafe function is unsafe
+    f(); //~ ERROR call to unsafe function is unsafe
+}
diff --git a/src/test/ui/async-await/async-unsafe-fn-call-in-safe.stderr b/src/test/ui/async-await/async-unsafe-fn-call-in-safe.stderr
new file mode 100644
index 00000000000..d22413beecb
--- /dev/null
+++ b/src/test/ui/async-await/async-unsafe-fn-call-in-safe.stderr
@@ -0,0 +1,35 @@
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> $DIR/async-unsafe-fn-call-in-safe.rs:14:5
+   |
+LL |     S::f();
+   |     ^^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> $DIR/async-unsafe-fn-call-in-safe.rs:15:5
+   |
+LL |     f();
+   |     ^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> $DIR/async-unsafe-fn-call-in-safe.rs:19:5
+   |
+LL |     S::f();
+   |     ^^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+  --> $DIR/async-unsafe-fn-call-in-safe.rs:20:5
+   |
+LL |     f();
+   |     ^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0133`.
diff --git a/src/test/ui/async-await/await-macro.rs b/src/test/ui/async-await/await-macro.rs
index c37835d73e9..b9cd3903513 100644
--- a/src/test/ui/async-await/await-macro.rs
+++ b/src/test/ui/async-await/await-macro.rs
@@ -77,6 +77,12 @@ fn async_closure(x: u8) -> impl Future<Output = u8> {
     })(x)
 }
 
+fn async_closure_in_unsafe_block(x: u8) -> impl Future<Output = u8> {
+    (unsafe {
+        async move |x: u8| unsafe_fn(await!(unsafe_async_fn(x)))
+    })(x)
+}
+
 async fn async_fn(x: u8) -> u8 {
     await!(wake_and_yield_once());
     x
@@ -127,6 +133,18 @@ async unsafe fn unsafe_async_fn(x: u8) -> u8 {
     x
 }
 
+unsafe fn unsafe_fn(x: u8) -> u8 {
+    x
+}
+
+fn async_block_in_unsafe_block(x: u8) -> impl Future<Output = u8> {
+    unsafe {
+        async move {
+            unsafe_fn(await!(unsafe_async_fn(x)))
+        }
+    }
+}
+
 struct Foo;
 
 trait Bar {
@@ -134,11 +152,15 @@ trait Bar {
 }
 
 impl Foo {
-    async fn async_method(x: u8) -> u8 {
+    async fn async_assoc_item(x: u8) -> u8 {
         unsafe {
             await!(unsafe_async_fn(x))
         }
     }
+
+    async unsafe fn async_unsafe_assoc_item(x: u8) -> u8 {
+        await!(unsafe_async_fn(x))
+    }
 }
 
 fn test_future_yields_once_then_returns<F, Fut>(f: F)
@@ -177,15 +199,22 @@ fn main() {
         async_block,
         async_nonmove_block,
         async_closure,
+        async_closure_in_unsafe_block,
         async_fn,
         generic_async_fn,
         async_fn_with_internal_borrow,
-        Foo::async_method,
+        async_block_in_unsafe_block,
+        Foo::async_assoc_item,
         |x| {
             async move {
                 unsafe { await!(unsafe_async_fn(x)) }
             }
         },
+        |x| {
+            async move {
+                unsafe { await!(Foo::async_unsafe_assoc_item(x)) }
+            }
+        },
     }
     test_with_borrow! {
         async_block_with_borrow_named_lifetime,
diff --git a/src/test/ui/consts/const-eval/infinite_loop.rs b/src/test/ui/consts/const-eval/infinite_loop.rs
index a2a45af7cb0..8fa5b0a961f 100644
--- a/src/test/ui/consts/const-eval/infinite_loop.rs
+++ b/src/test/ui/consts/const-eval/infinite_loop.rs
@@ -4,7 +4,9 @@ fn main() {
     let _ = [(); {
         //~^ WARNING Constant evaluating a complex constant, this might take some time
         let mut n = 113383; // #20 in https://oeis.org/A006884
-        while n != 0 { //~ ERROR constant contains unimplemented expression type
+        while n != 0 {
+        //~^ ERROR constant contains unimplemented expression type
+        //~| ERROR constant contains unimplemented expression type
             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
             //~^ ERROR evaluation of constant value failed
         }
diff --git a/src/test/ui/consts/const-eval/infinite_loop.stderr b/src/test/ui/consts/const-eval/infinite_loop.stderr
index 3a7da9ff2c8..68e7fdb1251 100644
--- a/src/test/ui/consts/const-eval/infinite_loop.stderr
+++ b/src/test/ui/consts/const-eval/infinite_loop.stderr
@@ -1,7 +1,15 @@
 error[E0019]: constant contains unimplemented expression type
+  --> $DIR/infinite_loop.rs:7:15
+   |
+LL |         while n != 0 {
+   |               ^^^^^^
+
+error[E0019]: constant contains unimplemented expression type
   --> $DIR/infinite_loop.rs:7:9
    |
 LL | /         while n != 0 {
+LL | |
+LL | |
 LL | |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
 LL | |
 LL | |         }
@@ -21,12 +29,12 @@ LL | |     }];
    | |_____^
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/infinite_loop.rs:8:20
+  --> $DIR/infinite_loop.rs:10:20
    |
 LL |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
    |                    ^^^^^^^^^^ duplicate interpreter state observed here, const evaluation will never terminate
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 Some errors have detailed explanations: E0019, E0080.
 For more information about an error, try `rustc --explain E0019`.
diff --git a/src/test/ui/consts/const-eval/issue-52442.rs b/src/test/ui/consts/const-eval/issue-52442.rs
index fadcde528d8..2989b200b2f 100644
--- a/src/test/ui/consts/const-eval/issue-52442.rs
+++ b/src/test/ui/consts/const-eval/issue-52442.rs
@@ -1,4 +1,5 @@
 fn main() {
-    [();  { &loop { break } as *const _ as usize } ]; //~ ERROR unimplemented expression type
-    //~^ ERROR it is undefined behavior to use this value
+    [();  { &loop { break } as *const _ as usize } ];
+    //~^ ERROR casting pointers to integers in constants is unstable
+    //~| ERROR it is undefined behavior to use this value
 }
diff --git a/src/test/ui/consts/const-eval/issue-52442.stderr b/src/test/ui/consts/const-eval/issue-52442.stderr
index e9afec5766a..88c94d917fe 100644
--- a/src/test/ui/consts/const-eval/issue-52442.stderr
+++ b/src/test/ui/consts/const-eval/issue-52442.stderr
@@ -1,8 +1,11 @@
-error[E0019]: constant contains unimplemented expression type
-  --> $DIR/issue-52442.rs:2:14
+error[E0658]: casting pointers to integers in constants is unstable
+  --> $DIR/issue-52442.rs:2:13
    |
 LL |     [();  { &loop { break } as *const _ as usize } ];
-   |              ^^^^^^^^^^^^^^
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/51910
+   = help: add `#![feature(const_raw_ptr_to_usize_cast)]` to the crate attributes to enable
 
 error[E0080]: it is undefined behavior to use this value
   --> $DIR/issue-52442.rs:2:11
@@ -14,5 +17,5 @@ LL |     [();  { &loop { break } as *const _ as usize } ];
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0019, E0080.
-For more information about an error, try `rustc --explain E0019`.
+Some errors have detailed explanations: E0080, E0658.
+For more information about an error, try `rustc --explain E0080`.
diff --git a/src/test/ui/consts/const-eval/issue-52475.rs b/src/test/ui/consts/const-eval/issue-52475.rs
index aafdd5fe617..b42249e57fa 100644
--- a/src/test/ui/consts/const-eval/issue-52475.rs
+++ b/src/test/ui/consts/const-eval/issue-52475.rs
@@ -3,7 +3,9 @@ fn main() {
         //~^ WARNING Constant evaluating a complex constant, this might take some time
         let mut x = &0;
         let mut n = 0;
-        while n < 5 { //~ ERROR constant contains unimplemented expression type
+        while n < 5 {
+        //~^ ERROR constant contains unimplemented expression type
+        //~| ERROR constant contains unimplemented expression type
             n = (n + 1) % 5; //~ ERROR evaluation of constant value failed
             x = &0; // Materialize a new AllocId
         }
diff --git a/src/test/ui/consts/const-eval/issue-52475.stderr b/src/test/ui/consts/const-eval/issue-52475.stderr
index 7a52a38d767..1e83cbcff2b 100644
--- a/src/test/ui/consts/const-eval/issue-52475.stderr
+++ b/src/test/ui/consts/const-eval/issue-52475.stderr
@@ -1,7 +1,15 @@
 error[E0019]: constant contains unimplemented expression type
+  --> $DIR/issue-52475.rs:6:15
+   |
+LL |         while n < 5 {
+   |               ^^^^^
+
+error[E0019]: constant contains unimplemented expression type
   --> $DIR/issue-52475.rs:6:9
    |
 LL | /         while n < 5 {
+LL | |
+LL | |
 LL | |             n = (n + 1) % 5;
 LL | |             x = &0; // Materialize a new AllocId
 LL | |         }
@@ -21,12 +29,12 @@ LL | |     }];
    | |_____^
 
 error[E0080]: evaluation of constant value failed
-  --> $DIR/issue-52475.rs:7:17
+  --> $DIR/issue-52475.rs:9:17
    |
 LL |             n = (n + 1) % 5;
    |                 ^^^^^^^^^^^ duplicate interpreter state observed here, const evaluation will never terminate
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 Some errors have detailed explanations: E0019, E0080.
 For more information about an error, try `rustc --explain E0019`.
diff --git a/src/test/ui/consts/const-eval/issue-62272.rs b/src/test/ui/consts/const-eval/issue-62272.rs
new file mode 100644
index 00000000000..ad8589c7378
--- /dev/null
+++ b/src/test/ui/consts/const-eval/issue-62272.rs
@@ -0,0 +1,9 @@
+// run-pass
+
+// Tests that `loop`s unconditionally-broken-from are allowed in constants.
+
+const FOO: () = loop { break; };
+
+fn main() {
+    [FOO; { let x; loop { x = 5; break; } x }];
+}
diff --git a/src/test/ui/consts/const-labeled-break.rs b/src/test/ui/consts/const-labeled-break.rs
index 512ad9427ea..36e308ade9c 100644
--- a/src/test/ui/consts/const-labeled-break.rs
+++ b/src/test/ui/consts/const-labeled-break.rs
@@ -1,9 +1,10 @@
+// run-pass
+
 // Using labeled break in a while loop has caused an illegal instruction being
 // generated, and an ICE later.
 //
 // See https://github.com/rust-lang/rust/issues/51350 for more information.
 
 const CRASH: () = 'a: while break 'a {};
-//~^ ERROR constant contains unimplemented expression type
 
 fn main() {}
diff --git a/src/test/ui/consts/const-labeled-break.stderr b/src/test/ui/consts/const-labeled-break.stderr
deleted file mode 100644
index 2009e922355..00000000000
--- a/src/test/ui/consts/const-labeled-break.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0019]: constant contains unimplemented expression type
-  --> $DIR/const-labeled-break.rs:6:19
-   |
-LL | const CRASH: () = 'a: while break 'a {};
-   |                   ^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0019`.
diff --git a/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.rs b/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.rs
deleted file mode 100644
index 33252019e71..00000000000
--- a/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-#![deny(deprecated)]
-#![feature(dropck_parametricity)]
-
-struct Foo;
-
-impl Drop for Foo {
-    #[unsafe_destructor_blind_to_params]
-    //~^ ERROR use of deprecated attribute `dropck_parametricity`
-    fn drop(&mut self) {}
-}
-
-fn main() {}
diff --git a/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.stderr b/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.stderr
deleted file mode 100644
index b6a474575c6..00000000000
--- a/src/test/ui/feature-gates/feature-gate-dropck-ugeh-2.stderr
+++ /dev/null
@@ -1,14 +0,0 @@
-error: use of deprecated attribute `dropck_parametricity`: unsafe_destructor_blind_to_params has been replaced by may_dangle and will be removed in the future. See https://github.com/rust-lang/rust/issues/34761
-  --> $DIR/feature-gate-dropck-ugeh-2.rs:7:5
-   |
-LL |     #[unsafe_destructor_blind_to_params]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace this attribute with `#[may_dangle]`
-   |
-note: lint level defined here
-  --> $DIR/feature-gate-dropck-ugeh-2.rs:1:9
-   |
-LL | #![deny(deprecated)]
-   |         ^^^^^^^^^^
-
-error: aborting due to previous error
-
diff --git a/src/test/ui/feature-gates/feature-gate-dropck-ugeh.rs b/src/test/ui/feature-gates/feature-gate-dropck-ugeh.rs
deleted file mode 100644
index a2377cda9bd..00000000000
--- a/src/test/ui/feature-gates/feature-gate-dropck-ugeh.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-// gate-test-dropck_parametricity
-
-// Ensure that attempts to use the unsafe attribute are feature-gated.
-// Example adapted from RFC 1238 text (just left out the feature gate).
-
-// https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md
-//     #example-of-the-unguarded-escape-hatch
-
-use std::cell::Cell;
-
-struct Concrete<'a>(u32, Cell<Option<&'a Concrete<'a>>>);
-
-struct Foo<T> { data: Vec<T> }
-
-impl<T> Drop for Foo<T> {
-    #[unsafe_destructor_blind_to_params] // This is the UGEH attribute
-    //~^ ERROR unsafe_destructor_blind_to_params has been replaced
-    //~| WARN use of deprecated attribute `dropck_parametricity`
-    fn drop(&mut self) { }
-}
-
-fn main() {
-    let mut foo = Foo {  data: Vec::new() };
-    foo.data.push(Concrete(0, Cell::new(None)));
-    foo.data.push(Concrete(0, Cell::new(None)));
-
-    foo.data[0].1.set(Some(&foo.data[1]));
-    foo.data[1].1.set(Some(&foo.data[0]));
-}
diff --git a/src/test/ui/feature-gates/feature-gate-dropck-ugeh.stderr b/src/test/ui/feature-gates/feature-gate-dropck-ugeh.stderr
deleted file mode 100644
index 581b760ba4f..00000000000
--- a/src/test/ui/feature-gates/feature-gate-dropck-ugeh.stderr
+++ /dev/null
@@ -1,20 +0,0 @@
-error[E0658]: unsafe_destructor_blind_to_params has been replaced by may_dangle and will be removed in the future
-  --> $DIR/feature-gate-dropck-ugeh.rs:16:5
-   |
-LL |     #[unsafe_destructor_blind_to_params] // This is the UGEH attribute
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/28498
-   = help: add `#![feature(dropck_parametricity)]` to the crate attributes to enable
-
-warning: use of deprecated attribute `dropck_parametricity`: unsafe_destructor_blind_to_params has been replaced by may_dangle and will be removed in the future. See https://github.com/rust-lang/rust/issues/34761
-  --> $DIR/feature-gate-dropck-ugeh.rs:16:5
-   |
-LL |     #[unsafe_destructor_blind_to_params] // This is the UGEH attribute
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace this attribute with `#[may_dangle]`
-   |
-   = note: #[warn(deprecated)] on by default
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/issues/issue-49919.rs b/src/test/ui/issues/issue-49919.rs
new file mode 100644
index 00000000000..780f338681d
--- /dev/null
+++ b/src/test/ui/issues/issue-49919.rs
@@ -0,0 +1,7 @@
+fn foo<'a, T: 'a>(t: T) -> Box<dyn Fn() -> &'a T + 'a> {
+    let foo: Box<dyn for <'c> Fn() -> &'c T> = Box::new(move || &t);
+    //~^ ERROR: binding for associated type
+    unimplemented!()
+}
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-49919.stderr b/src/test/ui/issues/issue-49919.stderr
new file mode 100644
index 00000000000..8098be5cc45
--- /dev/null
+++ b/src/test/ui/issues/issue-49919.stderr
@@ -0,0 +1,9 @@
+error[E0582]: binding for associated type `Output` references lifetime `'c`, which does not appear in the trait input types
+  --> $DIR/issue-49919.rs:2:39
+   |
+LL |     let foo: Box<dyn for <'c> Fn() -> &'c T> = Box::new(move || &t);
+   |                                       ^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0582`.
diff --git a/src/test/ui/issues/issue-55511.rs b/src/test/ui/issues/issue-55511.rs
index 42c6f24b36a..055886bf367 100644
--- a/src/test/ui/issues/issue-55511.rs
+++ b/src/test/ui/issues/issue-55511.rs
@@ -1,5 +1,5 @@
+#![warn(indirect_structural_match)]
 use std::cell::Cell;
-
 trait Foo<'a> {
     const C: Option<Cell<&'a u32>>;
 }
diff --git a/src/test/ui/issues/issue-55511.stderr b/src/test/ui/issues/issue-55511.stderr
index c0f702e4fab..e094256f5c8 100644
--- a/src/test/ui/issues/issue-55511.stderr
+++ b/src/test/ui/issues/issue-55511.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `std::cell::Cell` in a pattern, `std::cell::C
 LL |         <() as Foo<'static>>::C => { }
    |         ^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/issue-55511.rs:1:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/issues/issue-61858.rs b/src/test/ui/issues/issue-61858.rs
new file mode 100644
index 00000000000..6c3b56586c4
--- /dev/null
+++ b/src/test/ui/issues/issue-61858.rs
@@ -0,0 +1,3 @@
+fn main() {
+    (if foobar) //~ ERROR expected `{`, found `)`
+}
diff --git a/src/test/ui/issues/issue-61858.stderr b/src/test/ui/issues/issue-61858.stderr
new file mode 100644
index 00000000000..ea2ec3d013f
--- /dev/null
+++ b/src/test/ui/issues/issue-61858.stderr
@@ -0,0 +1,10 @@
+error: expected `{`, found `)`
+  --> $DIR/issue-61858.rs:2:15
+   |
+LL |     (if foobar)
+   |      --       ^ expected `{`
+   |      |
+   |      this `if` statement has a condition, but no block
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/rfc1445/allow-use-behind-cousin-variant.rs b/src/test/ui/rfc1445/allow-use-behind-cousin-variant.rs
new file mode 100644
index 00000000000..dca8aaef150
--- /dev/null
+++ b/src/test/ui/rfc1445/allow-use-behind-cousin-variant.rs
@@ -0,0 +1,59 @@
+// rust-lang/rust#62614: we want to allow matching on constants of types that
+// have non-structural-match variants, *if* the constant itself does not use
+// any such variant.
+
+// NOTE: for now, deliberately leaving the lint `indirect_structural_match` set
+// to its default, so that we will not issue a diangostic even if
+// rust-lang/rust#62614 remains an open issue.
+
+// run-pass
+
+struct Sum(u32, u32);
+
+impl PartialEq for Sum {
+    fn eq(&self, other: &Self) -> bool { self.0 + self.1 == other.0 + other.1 }
+}
+
+impl Eq for Sum { }
+
+#[derive(PartialEq, Eq)]
+enum Eek {
+    TheConst,
+    UnusedByTheConst(Sum)
+}
+
+const THE_CONST: Eek = Eek::TheConst;
+const SUM_THREE: Eek = Eek::UnusedByTheConst(Sum(3,0));
+
+const EEK_ZERO: &[Eek] = &[];
+const EEK_ONE: &[Eek] = &[THE_CONST];
+
+pub fn main() {
+    match Eek::UnusedByTheConst(Sum(1,2)) {
+        ref sum if sum == &SUM_THREE => { println!("Hello 0"); }
+        _ => { println!("Gbye"); }
+    }
+
+    match Eek::TheConst {
+        THE_CONST => { println!("Hello 1"); }
+        _ => { println!("Gbye"); }
+    }
+
+
+    match & &Eek::TheConst {
+        & & THE_CONST => { println!("Hello 2"); }
+        _ => { println!("Gbye"); }
+    }
+
+    match & & &[][..] {
+        & & EEK_ZERO => { println!("Hello 3"); }
+        & & EEK_ONE => { println!("Gbye"); }
+        _ => { println!("Gbye"); }
+    }
+
+    match & & &[Eek::TheConst][..] {
+        & & EEK_ZERO => { println!("Gby"); }
+        & & EEK_ONE => { println!("Hello 4"); }
+        _ => { println!("Gbye"); }
+    }
+}
diff --git a/src/test/ui/rfc1445/cant-hide-behind-direct-struct-param.rs b/src/test/ui/rfc1445/cant-hide-behind-direct-struct-param.rs
index a3a615ea748..584e7a00f09 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-direct-struct-param.rs
+++ b/src/test/ui/rfc1445/cant-hide-behind-direct-struct-param.rs
@@ -4,7 +4,7 @@
 // through that we had intended to reject.
 //
 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
-
+#![warn(indirect_structural_match)]
 struct NoDerive(i32);
 
 // This impl makes NoDerive irreflexive.
diff --git a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.rs b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.rs
index b6d9c52b298..0328db5a49c 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.rs
+++ b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.rs
@@ -4,7 +4,7 @@
 // through that we had intended to reject.
 //
 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
-
+#![warn(indirect_structural_match)]
 // run-pass
 
 struct NoDerive(i32);
diff --git a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.stderr b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.stderr
index 3de63f43ecb..5281d576066 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.stderr
+++ b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `NoDerive` in a pattern, `NoDerive` must be a
 LL |         WRAP_DOUBLY_INDIRECT_INLINE => { panic!("WRAP_DOUBLY_INDIRECT_INLINE matched itself"); }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/cant-hide-behind-doubly-indirect-embedded.rs:7:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.rs b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.rs
index 804d336b3ea..54579e487a6 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.rs
+++ b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.rs
@@ -4,7 +4,7 @@
 // through that we had intended to reject.
 //
 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
-
+#![warn(indirect_structural_match)]
 // run-pass
 
 struct NoDerive(i32);
diff --git a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.stderr b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.stderr
index ee4652d1532..5d601c2c006 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.stderr
+++ b/src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-param.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `NoDerive` in a pattern, `NoDerive` must be a
 LL |         WRAP_DOUBLY_INDIRECT_PARAM => { panic!("WRAP_DOUBLY_INDIRECT_PARAM matched itself"); }
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/cant-hide-behind-doubly-indirect-param.rs:7:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.rs b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.rs
index 85d2e65a9a0..2a24316898b 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.rs
+++ b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.rs
@@ -4,7 +4,7 @@
 // through that we had intended to reject.
 //
 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
-
+#![warn(indirect_structural_match)]
 // run-pass
 
 struct NoDerive(i32);
diff --git a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.stderr b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.stderr
index eb746849931..4ac19afa706 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.stderr
+++ b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-embedded.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `NoDerive` in a pattern, `NoDerive` must be a
 LL |         WRAP_INDIRECT_INLINE => { panic!("WRAP_INDIRECT_INLINE matched itself"); }
    |         ^^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/cant-hide-behind-indirect-struct-embedded.rs:7:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.rs b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.rs
index 849aa147766..64e777f2322 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.rs
+++ b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.rs
@@ -4,7 +4,7 @@
 // through that we had intended to reject.
 //
 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
-
+#![warn(indirect_structural_match)]
 // run-pass
 
 struct NoDerive(i32);
diff --git a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.stderr b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.stderr
index 8a165568444..4000a479878 100644
--- a/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.stderr
+++ b/src/test/ui/rfc1445/cant-hide-behind-indirect-struct-param.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `NoDerive` in a pattern, `NoDerive` must be a
 LL |         WRAP_INDIRECT_PARAM => { panic!("WRAP_INDIRECT_PARAM matched itself"); }
    |         ^^^^^^^^^^^^^^^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/cant-hide-behind-indirect-struct-param.rs:7:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.rs b/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.rs
index 7646f7558a3..98943a9666a 100644
--- a/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.rs
+++ b/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.rs
@@ -10,7 +10,7 @@
 
 // Issue 62307 pointed out a case where the checking for
 // `#[structural_match]` was too shallow.
-
+#![warn(indirect_structural_match)]
 // run-pass
 
 #[derive(Debug)]
diff --git a/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.stderr b/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.stderr
index ba0275f5f9f..0e158c2fda5 100644
--- a/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.stderr
+++ b/src/test/ui/rfc1445/issue-62307-match-ref-ref-forbidden-without-eq.stderr
@@ -4,7 +4,11 @@ warning: to use a constant of type `B` in a pattern, `B` must be annotated with
 LL |         RR_B1 => { println!("CLAIM RR0: {:?} matches {:?}", RR_B1, RR_B0); }
    |         ^^^^^
    |
-   = note: #[warn(indirect_structural_match)] on by default
+note: lint level defined here
+  --> $DIR/issue-62307-match-ref-ref-forbidden-without-eq.rs:13:9
+   |
+LL | #![warn(indirect_structural_match)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #62411 <https://github.com/rust-lang/rust/issues/62411>
 
diff --git a/src/test/ui/single-use-lifetime/one-use-in-fn-argument.rs b/src/test/ui/single-use-lifetime/one-use-in-fn-argument.rs
index 900e8434d4f..ff9d6bd01c6 100644
--- a/src/test/ui/single-use-lifetime/one-use-in-fn-argument.rs
+++ b/src/test/ui/single-use-lifetime/one-use-in-fn-argument.rs
@@ -9,4 +9,14 @@ fn a<'a>(x: &'a u32) { //~ ERROR `'a` only used once
     //~^ HELP elide the single-use lifetime
 }
 
+struct Single<'a> { x: &'a u32 }
+struct Double<'a, 'b> { f: &'a &'b u32 }
+
+fn center<'m>(_: Single<'m>) {} //~ ERROR `'m` only used once
+//~^ HELP elide the single-use lifetime
+fn left<'x, 'y>(foo: Double<'x, 'y>) -> &'x u32 { foo.f } //~ ERROR `'y` only used once
+//~^ HELP elide the single-use lifetime
+fn right<'x, 'y>(foo: Double<'x, 'y>) -> &'y u32 { foo.f } //~ ERROR `'x` only used once
+//~^ HELP elide the single-use lifetime
+
 fn main() { }
diff --git a/src/test/ui/single-use-lifetime/one-use-in-fn-argument.stderr b/src/test/ui/single-use-lifetime/one-use-in-fn-argument.stderr
index 4bf08534b8c..faaa7e2f1b0 100644
--- a/src/test/ui/single-use-lifetime/one-use-in-fn-argument.stderr
+++ b/src/test/ui/single-use-lifetime/one-use-in-fn-argument.stderr
@@ -16,5 +16,37 @@ help: elide the single-use lifetime
 LL | fn a(x: &u32) {
    |    --   --
 
-error: aborting due to previous error
+error: lifetime parameter `'m` only used once
+  --> $DIR/one-use-in-fn-argument.rs:15:11
+   |
+LL | fn center<'m>(_: Single<'m>) {}
+   |           ^^            -- ...is used only here
+   |           |
+   |           this lifetime...
+help: elide the single-use lifetime
+   |
+LL | fn center(_: Single<'_>) {}
+   |         --          ^^
+
+error: lifetime parameter `'y` only used once
+  --> $DIR/one-use-in-fn-argument.rs:17:13
+   |
+LL | fn left<'x, 'y>(foo: Double<'x, 'y>) -> &'x u32 { foo.f }
+   |             ^^ this lifetime... -- ...is used only here
+help: elide the single-use lifetime
+   |
+LL | fn left<'x>(foo: Double<'x, '_>) -> &'x u32 { foo.f }
+   |          --                 ^^
+
+error: lifetime parameter `'x` only used once
+  --> $DIR/one-use-in-fn-argument.rs:19:10
+   |
+LL | fn right<'x, 'y>(foo: Double<'x, 'y>) -> &'y u32 { foo.f }
+   |          ^^ this lifetime... -- ...is used only here
+help: elide the single-use lifetime
+   |
+LL | fn right<'y>(foo: Double<'_, 'y>) -> &'y u32 { foo.f }
+   |         --               ^^
+
+error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/span/issue28498-reject-lifetime-param.rs b/src/test/ui/span/issue28498-reject-lifetime-param.rs
index 9bc01766be5..1e719015785 100644
--- a/src/test/ui/span/issue28498-reject-lifetime-param.rs
+++ b/src/test/ui/span/issue28498-reject-lifetime-param.rs
@@ -16,9 +16,8 @@ struct Foo<'a>(u32, &'a ScribbleOnDrop);
 
 impl<'a> Drop for Foo<'a> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
-        // because destructor accesses borrowed data in `self.1`
-        // and we must force that to strictly outlive `self`.
+        // Use of `may_dangle` is unsound, because destructor accesses borrowed data
+        // in `self.1` and we must force that to strictly outlive `self`.
         println!("Dropping Foo({}, {:?})", self.0, self.1);
     }
 }
diff --git a/src/test/ui/span/issue28498-reject-lifetime-param.stderr b/src/test/ui/span/issue28498-reject-lifetime-param.stderr
index 1dcb40e5d9c..3119ddd03cc 100644
--- a/src/test/ui/span/issue28498-reject-lifetime-param.stderr
+++ b/src/test/ui/span/issue28498-reject-lifetime-param.stderr
@@ -1,5 +1,5 @@
 error[E0597]: `first_dropped` does not live long enough
-  --> $DIR/issue28498-reject-lifetime-param.rs:33:19
+  --> $DIR/issue28498-reject-lifetime-param.rs:32:19
    |
 LL |     foo1 = Foo(1, &first_dropped);
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough
diff --git a/src/test/ui/span/issue28498-reject-passed-to-fn.rs b/src/test/ui/span/issue28498-reject-passed-to-fn.rs
index c59de5df411..dcd2e9ad4ba 100644
--- a/src/test/ui/span/issue28498-reject-passed-to-fn.rs
+++ b/src/test/ui/span/issue28498-reject-passed-to-fn.rs
@@ -16,8 +16,7 @@ struct Foo<T>(u32, T, Box<for <'r> fn(&'r T) -> String>);
 
 impl<T> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
-        // because we pass `T` to the callback in `self.2`
+        // Use of `may_dangle` is unsound, because we pass `T` to the callback in `self.2`
         // below, and thus potentially read from borrowed data.
         println!("Dropping Foo({}, {})", self.0, (self.2)(&self.1));
     }
diff --git a/src/test/ui/span/issue28498-reject-passed-to-fn.stderr b/src/test/ui/span/issue28498-reject-passed-to-fn.stderr
index 214a6f6d65c..60e8a648cd5 100644
--- a/src/test/ui/span/issue28498-reject-passed-to-fn.stderr
+++ b/src/test/ui/span/issue28498-reject-passed-to-fn.stderr
@@ -1,5 +1,5 @@
 error[E0597]: `first_dropped` does not live long enough
-  --> $DIR/issue28498-reject-passed-to-fn.rs:35:19
+  --> $DIR/issue28498-reject-passed-to-fn.rs:34:19
    |
 LL |     foo1 = Foo(1, &first_dropped, Box::new(callback));
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough
diff --git a/src/test/ui/span/issue28498-reject-trait-bound.rs b/src/test/ui/span/issue28498-reject-trait-bound.rs
index 8813180c891..444cebb19a7 100644
--- a/src/test/ui/span/issue28498-reject-trait-bound.rs
+++ b/src/test/ui/span/issue28498-reject-trait-bound.rs
@@ -14,13 +14,12 @@ impl Drop for ScribbleOnDrop {
     }
 }
 
-struct Foo<T:fmt::Debug>(u32, T);
+struct Foo<T: fmt::Debug>(u32, T);
 
-impl<T:fmt::Debug> Drop for Foo<T> {
+impl<T: fmt::Debug> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
-        // because we access `T` fmt method when we pass `self.1`
-        // below, and thus potentially read from borrowed data.
+        // Use of `may_dangle` is unsound, because we access `T` fmt method when we pass
+        // `self.1` below, and thus potentially read from borrowed data.
         println!("Dropping Foo({}, {:?})", self.0, self.1);
     }
 }
diff --git a/src/test/ui/span/issue28498-reject-trait-bound.stderr b/src/test/ui/span/issue28498-reject-trait-bound.stderr
index d4fe291bef3..22e4a8205b6 100644
--- a/src/test/ui/span/issue28498-reject-trait-bound.stderr
+++ b/src/test/ui/span/issue28498-reject-trait-bound.stderr
@@ -1,5 +1,5 @@
 error[E0597]: `first_dropped` does not live long enough
-  --> $DIR/issue28498-reject-trait-bound.rs:35:19
+  --> $DIR/issue28498-reject-trait-bound.rs:34:19
    |
 LL |     foo1 = Foo(1, &first_dropped);
    |                   ^^^^^^^^^^^^^^ borrowed value does not live long enough