Auto merge of #110252 - matthiaskrgr:rollup-ovaixra, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #109810 (Replace rustdoc-ui/{c,z}-help tests with a stable run-make test )
 - #110035 (fix: ensure bad `#[test]` invocs retain correct AST)
 - #110089 (sync::mpsc: synchronize receiver disconnect with initialization)
 - #110103 (Report overflows gracefully with new solver)
 - #110122 (Fix x check --stage 1 when download-ci-llvm=false)
 - #110133 (Do not use ImplDerivedObligationCause for inherent impl method error reporting)
 - #110135 (Revert "Don't recover lifetimes/labels containing emojis as character literals")
 - #110235 (Fix `--extend-css` option)

Failed merges:

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

compiler/rustc_infer/src/traits/engine.rs

@@ -38,7 +38,7 @@ pub trait TraitEngine<'tcx>: 'tcx {
 
     fn select_where_possible(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 
-    fn collect_remaining_errors(&mut self) -> Vec<FulfillmentError<'tcx>>;
+    fn collect_remaining_errors(&mut self, infcx: &InferCtxt<'tcx>) -> Vec<FulfillmentError<'tcx>>;
 
     fn pending_obligations(&self) -> Vec<PredicateObligation<'tcx>>;
 
@@ -78,6 +78,6 @@ impl<'tcx, T: ?Sized + TraitEngine<'tcx>> TraitEngineExt<'tcx> for T {
             return errors;
         }
 
-        self.collect_remaining_errors()
+        self.collect_remaining_errors(infcx)
     }
 }

compiler/rustc_infer/src/traits/mod.rs

@@ -128,7 +128,11 @@ pub enum FulfillmentErrorCode<'tcx> {
     CodeProjectionError(MismatchedProjectionTypes<'tcx>),
     CodeSubtypeError(ExpectedFound<Ty<'tcx>>, TypeError<'tcx>), // always comes from a SubtypePredicate
     CodeConstEquateError(ExpectedFound<Const<'tcx>>, TypeError<'tcx>),
-    CodeAmbiguity,
+    CodeAmbiguity {
+        /// Overflow reported from the new solver `-Ztrait-solver=next`, which will
+        /// be reported as an regular error as opposed to a fatal error.
+        overflow: bool,
+    },
 }
 
 impl<'tcx, O> Obligation<'tcx, O> {

compiler/rustc_infer/src/traits/structural_impls.rs

@@ -46,7 +46,8 @@ impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
             super::CodeConstEquateError(ref a, ref b) => {
                 write!(f, "CodeConstEquateError({:?}, {:?})", a, b)
             }
-            super::CodeAmbiguity => write!(f, "Ambiguity"),
+            super::CodeAmbiguity { overflow: false } => write!(f, "Ambiguity"),
+            super::CodeAmbiguity { overflow: true } => write!(f, "Overflow"),
             super::CodeCycle(ref cycle) => write!(f, "Cycle({:?})", cycle),
         }
     }