Instead, report the error.
This emits the errors on-demand, without special-casing `impl Trait`, so
it should catch all ICEs of this kind, including ones that haven't been
found yet.
Since the error is emitted during type-checking there is less info about
the error; see comments in the code for details.
- Add test case for -> impl Trait
- Add test for impl trait with alias
- Move EmitIgnoredResolutionErrors to rustdoc
This makes `fn typeck_item_bodies` public, which is not desired behavior.
That change should be removed once
https://github.com/rust-lang/rust/pull/74070 is merged.
- Don't visit nested closures twice
