rust-lang#91913

Code changes in raw_vec require blessing UI tests every time

ACP: rust-lang/libs-team#156

Signed-off-by: Andrew Wock <ajwock@gmail.com>

I don't think it is necessary anymore. As I understand it from issue
39504 the original problem was that rustbuild changed a hardlink in the
cargo build dir to point to copy in the sysroot while cargo may have
hardlinked it to the original first. I don't think this happens anymore
and as such this workaround is no longer necessary.

Add Read Impl for &Stdin

r? `@oli-obk`
fixes rust-lang#95622

Add std::ffi::c_str module

ACP: rust-lang/libs-team#134

`std::ffi` docs before change:
![Structs: VaList, VaListImpl, CStr, CString, FromBytesWithNulError, FromVecWithNulError, IntoStringError, NulError, OsStr, OsString](https://github.com/rust-lang/rust/assets/15850505/b2cf3534-30f9-4ef0-a655-bacdc3a19e17)

`std::ffi` docs after change:
![Re-exports: self::c_str::{FromBytesWithNulError, FromBytesUntilNulError, FromVecWithNulError, NulError, IntoStringError} ; Modules: c_str ; Structs: VaList, VaListImpl, CStr, CString, OsStr, OsString](https://github.com/rust-lang/rust/assets/15850505/23aa6964-da7a-4942-bbf7-42bde2146f9e)

(note: I'm omitting the `c_int`, etc. stuff from the screenshots since it's the same in both. this doesn't just delete those types)

…nieu

Vec::try_with_capacity

Related to rust-lang#91913

Implements try_with_capacity for `Vec`, `VecDeque`, and `String`. I can follow it up with more collections if desired.

`Vec::try_with_capacity()` is functionally equivalent to the current stable:

```rust
let mut v = Vec::new();
v.try_reserve_exact(n)?
```

However, `try_reserve` calls non-inlined `finish_grow`, which requires old and new `Layout`, and is designed to reallocate memory. There is benefit to using `try_with_capacity`, besides syntax convenience, because it generates much smaller code at the call site with a direct call to the allocator. There's codegen test included.

It's also a very desirable functionality for users of `no_global_oom_handling` (Rust-for-Linux), since it makes a very commonly used function available in that environment (`with_capacity` is used much more frequently than all `(try_)reserve(_exact)`).

Implement MaybeUninit::fill{,_with,_from}

ACP: rust-lang/libs-team#156

…cjgillot

Misc improvements to non local defs lint implementation

This PR is a collection of small improvements I found when I [needlessly tried](https://www.github.com/rust-lang/rust/pull/120393#issuecomment-1971787475) to fix a "perf-regression" in the lint implementation.

I recommend looking at each commit individually.

Suggest correct path in include_bytes!

`include_bytes!` paths are relative, and I'm often not sure how nested is the `.rs` file that I'm editing, so I have to guess the number of `"../.."`. This change searches `..` and `../..` for the given file and offers corrected path as a suggestion.

I wasn't sure how to get the right span, and how to properly escape it.

```text
error: couldn't read src/file.txt: No such file or directory (os error 2)
 --> src/main.rs:2:13
  |
2 |     let x = include_bytes!("file.txt");
  |             ^^^^^^^^^^^^^^^----------^
  |                            |
  |                            help: it's in a parent directory: `"../../file.txt"`
```

Add a tidy check that checks whether the fluent slugs only appear once

As `@Nilstrieb` said in rust-lang#121828 (comment):
> Might make sense to have a tidy check that checks whether the fluent slugs only appear once in the source code and lint for that
there's a tidy check already for sorting

We can get the tidy check error:
```
tidy check
tidy error: /path/to/rust/compiler/rustc_const_eval/messages.ftl: message `const_eval_invalid_align` is not used
tidy error: /path/to/rust/compiler/rustc_lint/messages.ftl: message `lint_trivial_untranslatable_diag` is not used
tidy error: /path/to/rust/compiler/rustc_parse/messages.ftl: message `parse_invalid_literal_suffix` is not used
tidy error: /path/to/rust/compiler/rustc_infer/messages.ftl: message `infer_need_type_info_in_coroutine` is not used
tidy error: /path/to/rust/compiler/rustc_passes/messages.ftl: message `passes_expr_not_allowed_in_context` is not used
tidy error: /path/to/rust/compiler/rustc_passes/messages.ftl: message `passes_layout` is not used
tidy error: /path/to/rust/compiler/rustc_parse/messages.ftl: message `parse_not_supported` is not used
```

r? `@Nilstrieb`

…latest-edition, r=cjgillot

Eagerly translate `HelpUseLatestEdition` in parser diagnostics

Fixes rust-lang#122130.

This makes me suspicious of these other two usage of  `add_to_diagnostic()`. Would they *also* crash? I haven't attempted to construct test cases for them.

```
compiler/rustc_parse/src/parser/expr.rs
3453:            errors::HelpUseLatestEdition::new().add_to_diagnostic(e);

compiler/rustc_hir_typeck/src/expr.rs
2603:            HelpUseLatestEdition::new().add_to_diagnostic(&mut err);
```

This also seems like a footgun?

ci: add a runner for vanilla LLVM 18

For CI cost, this can be seen as replacing the llvm-15 runner we dropped in rust-lang#117947.

Also, I've set `IS_NOT_LATEST_LLVM` in the llvm-17 runner, since that's not the latest anymore.

…trochenkov

Remove a workaround for a bug

I don't think it is necessary anymore. As I understand it from issue 39504 the original problem was that rustbuild changed a hardlink in the cargo build dir to point to copy in the sysroot while cargo may have hardlinked it to the original first. I don't think this happens anymore and as such this workaround is no longer necessary.

Split out of rust-lang#120855

Some tweaks to the parallel query cycle handler

This renames `deadlock` to `break_query_cycles`. The abort logic is moved next to the thread spawning and gives the thread a name.

Fixes rust-lang#122035.

r? `@oli-obk`

Fix typo in `VisitorResult`

r? `@oli-obk`