Contrary to popular belief, `codegen_fulfill_obligation` does not get used solely in codegen, so we cannot rely on `param_env` being set to RevealAll and thus revealing the hidden types instead of constraining them.

This PR cleans up the rest of the spelling mistakes in the compiler comments. This PR does not change any literal or code spelling issues.

…-ou-se

Stabilize thread::is_finished

Closes rust-lang#90470.

r? `@m-ou-se`

… r=jackh726

Restore `impl Future<Output = Type>` to async blocks

I was sad when I undid some of the code I wrote in rust-lang#91096 in the PR rust-lang#95225, so I fixed it here to not print `[async output]`.

This PR "manually" normalizes the associated type `<[generator] as Generator>::Return` type which appears very frequently in `impl Future` types that result from async block desugaring.

Don't ICE when opaque types get their hidden type constrained again.

Contrary to popular belief, `codegen_fulfill_obligation` does not get used solely in codegen, so we cannot rely on `param_env` being set to RevealAll and thus revealing the hidden types instead of constraining them.

Fixes rust-lang#89312 (for real this time)

…aahc

Stabilize feature vec_retain_mut on Vec and VecDeque

Closes rust-lang#90829

…ompiler-errors

Spellchecking compiler comments

This PR cleans up the rest of the spelling mistakes in the compiler comments. This PR does not change any literal or code spelling issues.