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.

Renamings:
- find -> opt_hir_node
- get -> hir_node
- find_by_def_id -> opt_hir_node_by_def_id
- get_by_def_id -> hir_node_by_def_id

Fix rebase changes using removed methods

Use `tcx.hir_node_by_def_id()` whenever possible in compiler

Fix clippy errors

Fix compiler

Apply suggestions from code review

Co-authored-by: Vadim Petrochenkov <[email protected]>

Add FIXME for `tcx.hir()` returned type about its removal

Simplify with with `tcx.hir_node_by_def_id`

 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]>

…chenkov

[`RFC 3086`] Attempt to try to resolve blocking concerns

Implements what is described at rust-lang#83527 (comment) to hopefully make some progress.

It is unknown if such approach is or isn't desired due to the lack of further feedback, as such, it is probably best to nominate this PR to the official entities.

`@rustbot` labels +I-compiler-nominated

…trochenkov

Move some methods from `tcx.hir()` to `tcx`

rust-lang#118256 (comment)

Renamed:
- find -> opt_hir_node
- get -> hir_node
- find_by_def_id -> opt_hir_node_by_def_id
- get_by_def_id -> hir_node_by_def_id

…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