Rename files about error codes
fixes#60017
This PR will be failed in tidy.
<details>
<summary>The log is here:</summary>
```
tidy check
tidy error: duplicate error code: 411
tidy error: Documents\GitHub\rust\src\librustc_resolve\diagnostics.rs:83: __diagnostic_used!(E0411);
tidy error: Documents\GitHub\rust\src\librustc_resolve\diagnostics.rs:84: err.code(DiagnosticId::Error("E0411".to_owned()));
tidy error: duplicate error code: 424
tidy error: Documents\GitHub\rust\src\librustc_resolve\diagnostics.rs:90: debug!("smart_resolve_path_fragment: E0424, source={:?}", source);
tidy error: Documents\GitHub\rust\src\librustc_resolve\diagnostics.rs:92: __diagnostic_used!(E0424);
tidy error: Documents\GitHub\rust\src\librustc_resolve\diagnostics.rs:93: err.code(DiagnosticId::Error("E0424".to_owned()));
some tidy checks failed
```
</details>
I'd like to fix this but I don't know what to do.
I will work on later. Please let me know if you have any solutions.
r? @petrochenkov
The documentation for `rchunks_exact` said it started at the beginning
of the slice, bit it actually starts at the end of the slice.
In addition, there were a couple of "of the slice of the slice"
duplicate phrases going on for `rchunks_exact` and `rchunks_exact_mut`.
This fixes#60068.
Resolve inconsistency in error messages between "parameter" and "variable".
The inconsistency was introduced in 104fe1c4db (#33619), when a label saying `type variable` was added to an error with a message talking about `type parameters`.
Given that `parameter` is far more prevalent when referring to generics in the context of Rust, IMO it should be that in both the message and the label.
r? @nikomatsakis or @estebank
Remove collection-specific `with_capacity` documentation from `std::collections`
Fixes#59931
The style of `std::collections` module doc is very much a beginner friendly guide, and documenting niche, collection-specific behaviour feels out of place, if not brittle.
The note about `VecDeque` is outdated (see issue), and while `Vec` probably won't change its guarantees any time soon, the users who are interested in its allocation properties will find that in its own documentation.
Add test checking that Index<T: ?Sized> works
I've noticed that we have an `Idx: ?Sized` bound on the **index** in the `Index`, which seems strange given that we accept index by value. My guess is that it was meant to be removed in https://github.com/rust-lang/rust/pull/23601, but was overlooked.
If I remove this bound, `./x.py src/libstd/ src/libcore/` passes, which means at least that this is not covered by test.
I think there's three things we can do here:
* run crater with the bound removed to check if there are any regressions, and merge this, to be consistent with other operator traits
* run crater, get regressions, write a test for this with a note that "hey, we tried to fix it, its unfixable"
* decide, in the light of by-value DSTs, that this is a feature rather than a bug, and add a test
cc @rust-lang/libs
EDIT: the forth alternative is that there exist a genuine reason why this is the case, but I failed to see it :D
