Wrap coroutine variant fields in MaybeUninit to indicate that they
might be uninitialized. Otherwise an uninhabited field will make
the entire variant uninhabited and introduce undefined behaviour.

The analogous issue in the prefix of coroutine layout was addressed by
6fae7f8.

Stop allowing `rustc::potential_query_instability` in all of
`rustc_passes` and instead allow it on a case-by-case basis if it is
safe. In this case, all instances of the lint are safe to allow.

 filter_map_identity
 needless_bool
 search_is_some
 unit_arg
 map_identity
 needless_question_mark
 derivable_impls

add note that `missing_empty` is cleared now

Co-authored-by: Nadrieril <[email protected]>

…ty, r=compiler-errors

rustc_passes: Enforce `rustc::potential_query_instability` lint

Stop allowing `rustc::potential_query_instability` in all of `rustc_passes` and instead allow it on a case-by-case basis if it is safe. In this case, all instances of the lint are safe to allow.

Part of rust-lang#84447 which is E-help-wanted.

…lds, r=compiler-errors

Coroutine variant fields can be uninitialized

Wrap coroutine variant fields in MaybeUninit to indicate that they might be uninitialized. Otherwise an uninhabited field will make the entire variant uninhabited and introduce undefined behaviour.

The analogous issue in the prefix of coroutine layout was addressed by 6fae7f8.

…, r=notriddle

Add rustX check to codeblock attributes lint

We discovered this issue [here](rust-lang#118802 (comment)).

I assume that the issue will be present in other places outside of the compiler so it's worth adding a check for it.

First commit is just a small cleanup about variables creation which was a bit strange (at least more than necessary).

r? ``@notriddle``

…drieril

NFC: simplify merging of two vecs

…r-errors

clippy::complexity fixes

 filter_map_identity
 needless_bool
 search_is_some
 unit_arg
 map_identity
 needless_question_mark
 derivable_impls

…s, r=notriddle

Clean up variables in `search.js`

While reviewing rust-lang#118402, I saw a few small clean ups that were needed, mostly about variables creation.

r? ``@notriddle``

Typo