Or macro_rules hygiene, or mixed site hygiene. In other words, hygiene for variables and labels but not items.
The realization that made me implement this was that while "full" hygiene (aka. def site hygiene) is really hard for us to implement, and will likely involve intrusive changes and performance losses, since every `Name` will have to carry hygiene, mixed site hygiene is very local: it applies only to bodies, and we very well can save it in a side map with minor losses.
This fixes one diagnostic in r-a that was about `izip!()` using hygiene (yay!) but it introduces a huge number of others, because of #18262. Up until now this issue wasn't a major problem because it only affected few cases, but with hygiene identifiers referred by macros like that are not resolved at all. The next commit will fix that.
feat: render docs from aliased type when type has no docs
Trying to close#18344
- [x] ~Find the docs by traversing upwards if the type itself has none but aliasing for another type that might have.~
- [x] Show docs from aliased type.
- [x] Showing description that we are displaying documentation for different definition in hover box.
feat: respect references.exclude_tests in call-hierarchy
close#18212
### Changes
1. feat: respect `references.exclude_tests` in call-hierarchy
2. Modified the description of `references.exclude_tests`
internal: Don't resolve extern crates in import fix point resolution
The fix point loop won't progress them given the potential extern crate candidates are set up at build time.
feat: Highlight exit points of async blocks
Async blocks act similar to async functions in that the await keywords are related, but also act like functions where the exit points are related.
Fixes#18147
