StdoutLock and StderrLock does not have example, it would be better
to leave "see its documentation for more" like iter docs.

Turn the macro into a function. Also remove unused 'span' argument.

This version adds the ability to use `rdpmc` hardware-based performance
counters instead of wall-clock time for measuring duration. This also
introduces a dependency on the `perf-event-open-sys` crate on Linux
which is used when using hardware counters.

For some targets, rustc uses a "CRT fallback", where it links CRT
object files it ships instead of letting the host compiler link
them.

On musl, rustc currently links crt1, crti and crtn (provided by
libc), but does not link crtbegin and crtend (provided by libgcc).
In particular, crtend is responsible for terminating the .eh_frame
section. Lack of terminator may result in segfaults during
unwinding, as reported in rust-lang#47551 and encountered by the LLVM 12
update in rust-lang#81451.

This patch links crtbegin and crtend for musl as well, following
the table at the top of crt_objects.rs.

Like we say square root, not quadratic root.

Fixes rust-lang#82209

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

This indicates that the div is an interactive element, and makes the
sidebar toggle "clickable" in assistive technologies.

Fixes rust-lang#82582

In particular, the following program works on Linux, but deadlocks on
mac:

    use std::{
        sync::{Arc, RwLock},
        thread,
        time::Duration,
    };

    fn main() {
        let lock = Arc::new(RwLock::new(()));

        let r1 = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _rg = lock.read();
                eprintln!("r1/1");
                sleep(1000);

                let _rg = lock.read();
                eprintln!("r1/2");

                sleep(5000);
            }
        });
        sleep(100);
        let w = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _wg = lock.write();
                eprintln!("w");
            }
        });
        sleep(100);
        let r2 = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _rg = lock.read();
                eprintln!("r2");
                sleep(2000);
            }
        });

        r1.join().unwrap();
        r2.join().unwrap();
        w.join().unwrap();
    }

    fn sleep(ms: u64) {
        std::thread::sleep(Duration::from_millis(ms))
    }

Co-authored-by: Steven Fackler <sfackler@gmail.com>

This is necessary for Priroda.

Suggest character encoding is incorrect when encountering random null bytes

This adds a note whenever null bytes are seen at the start of a token unexpectedly, since those tend to come from UTF-16 encoded files without a [BOM](https://en.wikipedia.org/wiki/Byte_order_mark) (if a UTF-16 BOM appears it won't be valid UTF-8, but if there is no BOM it be both valid UTF-16 and valid but garbled UTF-8). This approach was suggested in rust-lang#73979 (comment).

Closes rust-lang#73979.

Add missing "see its documentation for more" stdio

StdoutLock and StderrLock does not have example, it would be better
to leave "see its documentation for more" like iter docs.

…hewjasper

Remove a redundant macro

Turn the macro into a function. Also remove unused 'span' argument.

…ewjasper

Use log level to control partitioning debug output

Link crtbegin/crtend on musl to terminate .eh_frame

For some targets, rustc uses a "CRT fallback", where it links CRT
object files it ships instead of letting the host compiler link
them.

On musl, rustc currently links crt1, crti and crtn (provided by
libc), but does not link crtbegin and crtend (provided by libgcc).
In particular, crtend is responsible for terminating the .eh_frame
section. Lack of terminator may result in segfaults during
unwinding, as reported in rust-lang#47551 and encountered by the LLVM 12
update in rust-lang#81451.

This patch links crtbegin and crtend for musl as well, following
the table at the top of crt_objects.rs.

r? ``@nagisa``

…-obk

Update measureme dependency to the latest version

This version adds the ability to use `rdpmc` hardware-based performance
counters instead of wall-clock time for measuring duration. This also
introduces a dependency on the `perf-event-open-sys` crate on Linux
which is used when using hardware counters.

r? ```@oli-obk```

doc: cube root, not cubic root

Like we say square root, not quadratic root.

…jyn514

Fix intra-doc handling of `Self` in enum

Fixes rust-lang#82209

Add ARIA role to sidebar toggle in Rustdoc

This indicates that the div is an interactive element, and makes the sidebar toggle "clickable" in assistive technologies.

Example of Vimium after this change has been applied (see the issue mentioned below for a screenshot of before):

![Screenshot of Vimium link hints on a Rustdoc page, indicating that the sidebar toggle is clickable](https://user-images.githubusercontent.com/1552853/109384961-ff935400-78f8-11eb-8199-1d35181aeff0.png)

Fixes rust-lang#82582

clarify RW lock's priority gotcha

In particular, the following program works on Linux, but deadlocks on
mac:

```rust
    use std::{
        sync::{Arc, RwLock},
        thread,
        time::Duration,
    };

    fn main() {
        let lock = Arc::new(RwLock::new(()));

        let r1 = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _rg = lock.read();
                eprintln!("r1/1");
                sleep(1000);

                let _rg = lock.read();
                eprintln!("r1/2");

                sleep(5000);
            }
        });
        sleep(100);
        let w = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _wg = lock.write();
                eprintln!("w");
            }
        });
        sleep(100);
        let r2 = thread::spawn({
            let lock = Arc::clone(&lock);
            move || {
                let _rg = lock.read();
                eprintln!("r2");
                sleep(2000);
            }
        });

        r1.join().unwrap();
        r2.join().unwrap();
        w.join().unwrap();
    }

    fn sleep(ms: u64) {
        std::thread::sleep(Duration::from_millis(ms))
    }
```

Context: I was completely mystified by a my CI deadlocking on mac ([here](matklad/xshell#7)), until ``@azdavis`` debugged the issue. See a stand-alone reproduciton here: matklad/xshell#15

Add a getter for Frame.loc

This is necessary for Priroda.

For context see https://rust-lang.zulipchat.com/#narrow/stream/146212-t-compiler.2Fconst-eval/topic/Frame.3A.3Aloc.20no.20longer.20public/near/228070266 and oli-obk/priroda#27.

cc `@DJMcNab`

r? `@RalfJung`