…rection

It's no longer necessary, as there is no license header anymore.

This change was accidentally introduced while removing license headers.

…cumentation"

This reverts commit 9c7b69e.

This is a non-POSIX extension implemented in Solaris and in glibc 2.29.
With this we can still use `posix_spawn()` when `Command::current_dir()`
has been set, otherwise we fallback to `fork(); chdir(); exec()`.

Since `compiler_builtins` is being injected automatically, its docs
aren't masked. This commit masks the crate's docs if it's brought in as
an extern crate.

The script was made unusable after removing license headers.

Closes rust-lang#58474.

Fix rust-lang#57730

cc rust-lang#57730

r? @cramertj

…ey, r=SimonSapin

Stabilize slice_sort_by_cached_key

I was going to ask on the tracking issue (rust-lang#34447), but decided to just send this and hope for an FCP here.  The method was added last March by rust-lang#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 rust-lang#34447

… r=oli-obk

Add specific feature gate error for const-unstable features

Before:
```
error: `impl Trait` in const fn is unstable
 --> src/lib.rs:7:19
  |
7 | const fn foo() -> impl T {
  |                   ^^^^^^

error: aborting due to previous error
```

After:
```
error[E0723]: `impl Trait` in const fn is unstable (see issue rust-lang#57563)
 --> src/lib.rs:7:19
  |
7 | const fn foo() -> impl T {
  |                   ^^^^^^
  = help: add #![feature(const_fn)] to the crate attributes to enable

error: aborting due to previous error
```

This improves the situation with rust-lang#57563. Fixes rust-lang#57544. Fixes rust-lang#54469.

r? @oli-obk

Remove code for updating copyright years in generate-deriving-span-tests

It's no longer necessary, as there is no license header anymore.

…y, r=QuietMisdreavus

Don't default on std crate when manipulating browser history

Fixes rust-lang#58263.

r? @QuietMisdreavus

librustc_mir: use ? in impl_snapshot_for! macro

fix Box::into_unique effecitvely transmuting to a raw ptr

Miri/Stacked Borrows treat `Box` specially: they assert that it is unique, and tag it appropriately. However, currently, `Box::into_inner` is not aware of that and returns a raw pointer (wrapped in a `Unique`) that carries the same tag as the box, meaning it carries a `Uniq` tag. This leads to all sorts of problems when people use the raw pointer they get out of the `Unique` type.

In the future, it'd be interesting to make `Unique` also carry some kind of uniqueness. In that case, something like this would instead be needed whenever a raw pointer is extracted from a `Unique`. However, that is out-of-scope for the current version of Stacked Borrows. So until then, this changes `into_unique` to perform a proper reference-to-raw-ptr-cast, which clears the tag.

Update which libcore/liballoc tests Miri ignores, and document why

…dchdir_np, r=alexcrichton

Use posix_spawn_file_actions_addchdir_np when possible

This is a non-POSIX extension implemented in Solaris and in glibc 2.29.
With this we can still use `posix_spawn()` when `Command::current_dir()`
has been set, otherwise we fallback to `fork(); chdir(); exec()`.

Whitelist the ARM v6 target-feature

…sdreavus

rustdoc: mask `compiler_builtins` docs

Fixes rust-lang#46783.

I wasn't able to fully confirm the underlying cause, but my theory is that functions in `compiler_builtins` were overwriting functions with the same names in libcore in the search index. Since the functions in `compiler_builtins` didn't have docs, that's why they weren't appearing in the results.

Masking the `compiler_builtins` crate fixes the search results. It appears that this crate was accidentally unmasked in rust-lang#49503.

split MaybeUninit into several features, expand docs a bit

This splits the `maybe_uninit` feature gate into several:

* `maybe_uninit` for what we will hopefully stabilize soon-ish.
* `maybe_uninit_ref` for creating references into `MaybeUninit`, for which the rules are not yet clear.
* `maybe_uninit_slice` for handling slices of `MaybeUninit`, which needs more API design work.
* `maybe_uninit_array` for creating arrays of `MaybeUninit` using a macro (because we don't have rust-lang#49147 yet).

Is that an okay thing to do? The goal is to help people avoid APIs we do not want to stabilize yet. I used this to make sure rustc itself does not use `get_ref` and `get_mut`.

I also extended the docs to advise against uninitialized integers -- again this is something for which the rules are still being discussed.

…n_unused_result, r=oli-obk

compile-pass test for rust-lang#53606

fixes rust-lang#53606

…r, r=alexcrichton

Fix runtime error in generate-keyword-tests

The script was made unusable after removing license headers.

…tyle-files, r=ollie27

Rustdoc remove old style files

Reopening of rust-lang#56577 (which I can't seem to reopen...).

I made the flag unstable so with this change, what was blocking the PR is now gone I assume.

Instant::checked_duration_since

…frewsxcv

Fix documentation for std::path::PathBuf::pop

Closes rust-lang#58474.

…ate_maintainers, r=oli-obk

Notify myself when Clippy toolstate changes

…tboats

Fix tracking issue for error iterators