hir: Disallow `target_feature` on constants
Fixes#64768.
This PR fixes an ICE when `#[target_feature]` is applied to constants by disallowing this with the same error as when `#[target_feature]` is applied to other places it shouldn't be.
I couldn't see anything in the [RFC](https://github.com/rust-lang/rfcs/blob/master/text/2045-target-feature.md) that suggested that `#[target_feature]` should be applicable to constants or any tests that suggested it should, though I might have missed something - if this is desirable in future, it remains possible to remove this error (but for the time being, I think this error is better than an ICE).
I also added some extra cases to the test for other places where `#[target_feature]` should not be permitted.
cc @gnzlbg
Account for tail expressions when pointing at return type
When there's a type mismatch we make an effort to check if it was
caused by a function's return type. This logic now makes sure to
only point at the return type if the error happens in a tail
expression.
Turn `walk_parent_nodes` method into an iterator.
CC #39968, CC #40799.
Remove unused DepTrackingMap
Deletes some related code (MemoizationMap trait, etc.)
I believe this became unused with red/green incremental introduction, but am uncertain.
Include message on tests that should panic but do not
As per issue #60790 includes a message for tests marked `#[should_panic]` that do not panic as expected.
Fixes#60790.
Docs: slice elements are equidistant
Recently, someone asked why `[char]` and `str` are not interchangeable, and I explained that in a slice, the elements must be laid out equidistantly, whereas the chars in a `str` are stored compactly regardless their size. However I couldn't find this documented anywhere, so here's a small addition of this fact.
There's no longer two distinct gcx and tcx lifetimes which made this
necessary (or, at least, the code compiles -- it's possible we got
better at normalizing, but that seems unlikely).
submodules: update clippy from 68ff8b19 to edd90473
Changes:
````
Remove clippy::author attribute from trailing_zeroes test
Move author issue test to author subdir
Fix author lint
Rustup to rust-lang/rust#64813
Refactor `booleans`
Detect assignment ops in integer_arithmetic
````
Fixes#64843
r? @oli-obk @Manishearth
Changes:
````
Remove clippy::author attribute from trailing_zeroes test
Move author issue test to author subdir
Fix author lint
Rustup to rust-lang/rust#64813
Refactor `booleans`
Detect assignment ops in integer_arithmetic
````
