The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
`visit_place` when optimization is performed.

Relax assertion check to allow the return place in var debug info.

This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in:

```
pub fn b(s: String) -> String {
    a(s)
}

#[inline]
pub fn a(s: String) -> String {
    let x = s;
    let y = x;
    y
}
```

Fixes rust-lang#76182

This is an alternative to PR rust-lang#76188

These tokens are not preserved in the AST in certain cases
(e.g. a leading `|` in a pattern or a trailing `+` in a trait bound).

This PR ignores them entirely during the pretty-print/reparse check
to avoid spuriously using the re-parsed tokenstream.

These tests will fall without the next commit.

Apply suggestions from code review

Co-authored-by: Joshua Nelson <joshua@yottadb.com>

case

Make the following methods of `Duration` unstable const under `duration_const_2`:
 - `from_secs_f64`
 - `from_secs_f32`
 - `mul_f64`
 - `mul_f32`
 - `div_f64`
 - `div_f32`

This results in all methods of `Duration` being (unstable) const.

Also adds tests for these methods in a const context, moved the test to `library` as part of rust-lang#76268.

Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const.

Tracking issue: rust-lang#72440

* Fix `const-display.rs` XPATH queries

* Add `issue_76501.rs` test file

* Rename issue_76501.rs to issue-76501.rs

This avoids missing a shared build when uplifting LLVM artifacts into the
sysroot. We were already producing a shared link anyway, though, so this is not
a visible change from the end user's perspective.

This note is not relevant to other operating systems.

…morse

NRVO: Allow occurrences of the return place in var debug info

The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
`visit_place` when optimization is performed.

Relax assertion check to allow the return place in var debug info.

This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in:

```rust
pub fn b(s: String) -> String {
    a(s)
}

#[inline]
pub fn a(s: String) -> String {
    let x = s;
    let y = x;
    y
}
```

…orse

Make all methods of `Duration` unstably const

Make the following methods of `Duration` unstable const under `duration_const_2`:
 - `from_secs_f64`
 - `from_secs_f32`
 - `mul_f64`
 - `mul_f32`
 - `div_f64`
 - `div_f32`

This results in all methods of `Duration` being (unstable) const.

Moved the tests to `library` as part of rust-lang#76268.

Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const.

Tracking issue: rust-lang#72440

r? @ecstatic-morse

…hton

Download LLVM from CI to bootstrap (linux-only to start)

This follows rust-lang#76332, adding support for using CI-built LLVM rather than building it locally. This should essentially "just work," but is left off by default in this PR.

While we can support downloading LLVM for multiple host triples, this currently only downloads it for the build triple. That said, it should be possible to expand this relatively easily should multiple host triples be desired. Most people shouldn't be adjusting host/target triples though, so this should cover most use cases.

Currently this downloads LLVM for the last bors-authored commit in the `git log`. This is a bit suboptimal -- we want the last bors-authored commit that touched the llvm-project submodule in basically all cases. But for now this just adds an extra ~20 MB download when rebasing atop latest master. Once we have a submodule bump landing after rust-lang#76332, we can fix this behavior to reduce downloads further.

…n514

Ignore rustc_private items from std docs

By ignoring rustc_private items for non local impl block,
this may fix rust-lang#74672 and fix rust-lang#75588 .

This might suppress rust-lang#76529 if it is simple enough for backport.

…chenkov

Ignore `|` and `+` tokens during proc-macro pretty-print check

Fixes rust-lang#76182

This is an alternative to PR rust-lang#76188

These tokens are not preserved in the AST in certain cases
(e.g. a leading `|` in a pattern or a trailing `+` in a trait bound).

This PR ignores them entirely during the pretty-print/reparse check
to avoid spuriously using the re-parsed tokenstream.

…k-Simulacrum

Add a dedicated debug-logging option to config.toml

@Mark-Simulacrum and I were talking in zulip and we found that turning on debug/trace logging in rustc is fairly confusing, as it effectively depends on debug-assertions and is not documented as such. @Mark-Simulacrum mentioned that we should probably have a separate option for logging anyways.

this diff adds that, having the option follow debug-assertions (so everyone's existing config.toml should be fine) and if the option is false

to test I ran ./x.py test <something> twice, once with `debug-logging = false` and once with `debug-logging = true` and made sure i only saw trace's when it was true

…stebank

Fixing memory exhaustion when formatting short code suggestion

Details can be found in issue rust-lang#76597. This PR replaces substractions with `saturating_sub`'s to avoid usize wrapping leading to memory exhaustion when formatting short suggestion messages.

Use `is_unstable_const_fn` instead of `is_min_const_fn` in rustdoc where appropriate

This closes rust-lang#76501. Specifically, it allows for nightly users with the `#![feature(const_fn)]` flag enabled to still have their `const fn` declarations documented as such, while retaining the desired behavior that rustdoc *not* document functions that have the `rustc_const_unstable` attribute as `const`.

Simplify iter zip struct doc

Some cleanup changes and commenting

r? @nikomatsakis
Cc @eddyb

Add mailmap entry

…s-note, r=Mark-Simulacrum

Remove Windows details from Unix and VmWorks symlink() docstrings

This note is not relevant to other operating systems.