Auto merge of #126951 - matthiaskrgr:rollup-xg0o4mc, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #126618 (Mark assoc tys live only if the corresponding trait is live)
 - #126746 (Deny `use<>` for RPITITs)
 - #126868 (not use offset when there is not ends with brace)
 - #126884 (Do not ICE when suggesting dereferencing closure arg)
 - #126893 (Eliminate the distinction between PREC_POSTFIX and PREC_PAREN precedence level)
 - #126915 (Don't suggest awaiting in closure patterns)
 - #126943 (De-duplicate all consecutive native libs regardless of their options)

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

compiler/rustc_ast_lowering/messages.ftl

@@ -130,6 +130,9 @@ ast_lowering_never_pattern_with_guard =
 
 ast_lowering_no_precise_captures_on_apit = `use<...>` precise capturing syntax not allowed in argument-position `impl Trait`
 
+ast_lowering_no_precise_captures_on_rpitit = `use<...>` precise capturing syntax is currently not allowed in return-position `impl Trait` in traits
+    .note = currently, return-position `impl Trait` in traits and trait implementations capture all lifetimes in scope
+
 ast_lowering_previously_used_here = previously used here
 
 ast_lowering_register1 = register `{$reg1_name}`

compiler/rustc_ast_lowering/src/errors.rs

@@ -424,6 +424,14 @@ pub(crate) struct NoPreciseCapturesOnApit {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(ast_lowering_no_precise_captures_on_rpitit)]
+#[note]
+pub(crate) struct NoPreciseCapturesOnRpitit {
+    #[primary_span]
+    pub span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(ast_lowering_yield_in_closure)]
 pub(crate) struct YieldInClosure {

compiler/rustc_ast_lowering/src/lib.rs

@@ -1594,6 +1594,26 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         };
         debug!(?captured_lifetimes_to_duplicate);
 
+        match fn_kind {
+            // Deny `use<>` on RPITIT in trait/trait-impl for now.
+            Some(FnDeclKind::Trait | FnDeclKind::Impl) => {
+                if let Some(span) = bounds.iter().find_map(|bound| match *bound {
+                    ast::GenericBound::Use(_, span) => Some(span),
+                    _ => None,
+                }) {
+                    self.tcx.dcx().emit_err(errors::NoPreciseCapturesOnRpitit { span });
+                }
+            }
+            None
+            | Some(
+                FnDeclKind::Fn
+                | FnDeclKind::Inherent
+                | FnDeclKind::ExternFn
+                | FnDeclKind::Closure
+                | FnDeclKind::Pointer,
+            ) => {}
+        }
+
         self.lower_opaque_inner(
             opaque_ty_node_id,
             origin,