This is no longer used by the index generator and was always an unstable
compiler detail, so strip it out.
This also leaves in RUSTC_ERROR_METADATA_DST since the stage0 compiler
still needs it to be set.
Implement another internal lints
cc #49509
This adds ~~two~~ one internal lint~~s~~:
1. LINT_PASS_IMPL_WITHOUT_MACRO: Make sure, that the `{declare,impl}_lint_pass` macro is used to implement lint passes. cc #59669
2. ~~USAGE_OF_TYCTXT_AND_SPAN_ARGS: item 2 on the list in #49509~~
~~With 2. I wasn't sure, if this lint should be applied everywhere. That means a careful review of 0955835 would be great. Also 73fb9b4 allows this lint on some functions. Should I also apply this lint there?~~
TODO (not directly relevant for review):
- [ ] https://github.com/rust-lang/rust/pull/59316#discussion_r280186517 (not sure yet, if this works or how to query for `rustc_private`, since it's not in [`Features`](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/feature_gate/struct.Features.html) 🤔 cc @eddyb)
- [x] https://github.com/rust-lang/rust/pull/61735#discussion_r292389870
- [x] Check explicitly for the `{declare,impl}_lint_pass!` macros
r? @oli-obk
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
Stabilize slice_sort_by_cached_key
I was going to ask on the tracking issue (https://github.com/rust-lang/rust/issues/34447), but decided to just send this and hope for an FCP here. The method was added last March by https://github.com/rust-lang/rust/pull/48639.
Signature: https://doc.rust-lang.org/std/primitive.slice.html#method.sort_by_cached_key
```rust
impl [T] {
pub fn sort_by_cached_key<K, F>(&mut self, f: F)
where F: FnMut(&T) -> K, K: Ord;
}
```
That's an identical signature to the existing `sort_by_key`, so I think the questions are just naming, implementation, and the usual "do we want this?".
The implementation seems to have proven its use in rustc at least, which many uses: https://github.com/rust-lang/rust/search?l=Rust&q=sort_by_cached_key
(I'm asking because it's exactly what I just needed the other day:
```rust
all_positions.sort_by_cached_key(|&n|
data::CITIES.iter()
.map(|x| *metric_closure.get_edge(n, x.pos).unwrap())
.sum::<usize>()
);
```
since caching that key is a pretty obviously good idea.)
Closes#34447
Rename rustc_errors dependency in rust 2018 crates
I think this is a better solution than `use rustc_errors as errors` in `lib.rs` and `use crate::errors` in modules.
Related: rust-lang/cargo#5653
cc #58099
r? @Centril
