Co-authored-by: Josh Triplett <josh@joshtriplett.org>

This is a follow-up of
rust-lang@75aec47.
There, I updated the wrapper to only include llvm/ADT/Optional.h for
LLVM version below 16. But I missed updating some of the None references.

Found by our experimental rust + llvm at HEAD bot:
https://buildkite.com/llvm-project/rust-llvm-integrate-prototype/builds/15587#0185006b-e0af-49e5-8b06-280ed125ff0d/200-539

Better documentation for env::home_dir()'s broken behaviour

This improves the documentation to say *why* it was deprecated. The reason was because it reads `HOME` on Windows which is meaningless there. Note that the PR that deprecated it stated that returning an empty string if `HOME` is set to an empty string was a problem, however I can find no evidence that this is the case. `cd` handles it fine whereas if `HOME` is unset it gives an explicit `HOME not set` error.

* Original deprecation reason: https://internals.rust-lang.org/t/deprecate-or-break-fix-std-env-home-dir/7315
* Original deprecation PR: rust-lang#51656

See rust-lang#71684

…eck, r=nagisa

Don't call `diagnostic_hir_wf_check` query if we have infer variables

Fixes rust-lang#105260

…KO8Ki

Detect spurious ; before assoc fn body

Fixes rust-lang#105226

r? ``@TaKO8Ki``

…s, r=oli-obk

Make encode_info_for_trait_item use queries instead of accessing the HIR

This change avoids accessing the HIR on `encode_info_for_trait_item` and uses queries. We will need to execute this function for elements that have no HIR and by using queries we will be able to feed for definitions that have no HIR.

r? ``@oli-obk``

…nagisa

separate heading from body

llvm-wrapper: adapt for LLVM API changes

This is a follow-up of rust-lang@75aec47. There, I updated the wrapper to only include llvm/ADT/Optional.h for LLVM version below 16. But I missed updating some of the None references.

Found by our experimental rust + llvm at HEAD bot: https://buildkite.com/llvm-project/rust-llvm-integrate-prototype/builds/15587#0185006b-e0af-49e5-8b06-280ed125ff0d/200-539

…tag-prep-line, r=notriddle

Extend rustdoc hashtag prepended line test

Follow-up of rust-lang#105539. This case wasn't checked so better add it.

r? `@notriddle`