…ytes, r=the8472

Specialize `Bytes` on `StdinLock<'_>`

I noticed recently, while profiling a little project, that I was spending a lot of time reading from stdin (even with locking). I was using the `.bytes()` iterator adaptor; I figured, since `StdinLock` is a `BufReader` internally, it would work just as fast. But this is not the case, as `Bytes` is only specialized for the raw `BufReader`, and not the `StdinLock`/`MutexGuard` wrapper. Performance improved significantly when I wrapped the lock in a new `BufReader`, but I was still a bit sore about the double buffer indirection.

This PR attempts to specialize it, by simply calling the already specialized implementation on `BufReader`.

…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#107464 (Add `str::Lines::remainder`)
 - rust-lang#118803 (Add the `min_exhaustive_patterns` feature gate)
 - rust-lang#119466 (Initial implementation of `str::from_raw_parts[_mut]`)
 - rust-lang#120053 (Specialize `Bytes` on `StdinLock<'_>`)
 - rust-lang#120124 (Split assembly tests for ELF and MachO)
 - rust-lang#120204 (Builtin macros effectively have implicit #[collapse_debuginfo(yes)])
 - rust-lang#120322 (Don't manually resolve async closures in `rustc_resolve`)
 - rust-lang#120356 (Fix broken markdown in csky-unknown-linux-gnuabiv2.md)

r? `@ghost`
`@rustbot` modify labels: rollup

…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#107464 (Add `str::Lines::remainder`)
 - rust-lang#118803 (Add the `min_exhaustive_patterns` feature gate)
 - rust-lang#119466 (Initial implementation of `str::from_raw_parts[_mut]`)
 - rust-lang#120053 (Specialize `Bytes` on `StdinLock<'_>`)
 - rust-lang#120124 (Split assembly tests for ELF and MachO)
 - rust-lang#120204 (Builtin macros effectively have implicit #[collapse_debuginfo(yes)])
 - rust-lang#120322 (Don't manually resolve async closures in `rustc_resolve`)
 - rust-lang#120356 (Fix broken markdown in csky-unknown-linux-gnuabiv2.md)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#120053 - AldanTanneo:specialize-stdinlock-bytes, r=the8472

Specialize `Bytes` on `StdinLock<'_>`

I noticed recently, while profiling a little project, that I was spending a lot of time reading from stdin (even with locking). I was using the `.bytes()` iterator adaptor; I figured, since `StdinLock` is a `BufReader` internally, it would work just as fast. But this is not the case, as `Bytes` is only specialized for the raw `BufReader`, and not the `StdinLock`/`MutexGuard` wrapper. Performance improved significantly when I wrapped the lock in a new `BufReader`, but I was still a bit sore about the double buffer indirection.

This PR attempts to specialize it, by simply calling the already specialized implementation on `BufReader`.