This reduces by 12% the number of allocations done for a "clean
incremental" of `webrender_api`, which reduces the instruction count by
about 0.5%.

It also reduces instruction counts by up to 1.4% across a range of
rustc-perf benchmark runs.

Combine all builtin late lints and make lint checking parallel

Blocked on rust-lang#57293.

Cuts runtime of late lint checking from 3.222s to 0.546s with 8 threads on `winapi` (@retep998 ;) )

r? @estebank

Use `track_errors` instead of hand rolling

Fixes rust-lang#59215

r? @oli-obk

…Centril

warn -> deny duplicate match bindings

This is the next step of rust-lang#57742

r? @Centril

- [x] Decide whether to go to deny-by-default or hard error.
     - My preference is to make this deny-by-default, rather than going straight to a hard error. The CI should fail because I haven't updated the ui test yet. I'll update it when we decide which to do.
- [x] Update [test](https://github.com/mark-i-m/rust/blob/c25d6b83441e0c060ee0273193ef27b29e1318cd/src/test/ui/macros/macro-multiple-matcher-bindings.rs)
- [ ] ~Crater run~ see rust-lang#59394 (comment)

…es, r=alexcrichton

bootstrap: build crates under libtest with -Z emit-stack-sizes

Please see the comment in the diff for the rationale.

This change adds a `.stack_sizes` linker section to `libcompiler_builtins.rlib`
but this section is discarded by the linker by default so it won't affect the
binary size of most programs. It will, however, negatively affect the binary
size of programs that link to a recent release of the `cortex-m-rt` crate
because of the linker script that crate provides, but I have proposed a PR
(rust-embedded/cortex-m-rt#186) to solve the problem (which I originally
introduced :-)).

This change does increase the size of the `libcompiler_builtins.rlib` artifact we
distribute but the increase is in the order of (a few) KBs.

r? @alexcrichton

…chenkov

Visit path in `walk_mac`

Fixes rust-lang#54110.

musl: build toolchain libs with -fPIC

Fixes rust-lang#59411

…lVec, r=petrochenkov

Use `SmallVec` in `TokenStreamBuilder`.

This reduces by 12% the number of allocations done for a "clean incremental" of `webrender_api`, which reduces the instruction count by about 0.5%.

r? @petrochenkov

Remove unnecessary with_globals calls

Use 'write_all' instead of 'write' in example code

Using `write` without looping and checking the result can cause silent data loss.  Example code should use `write_all` so that people don't copy this pattern.  (Of course this does not include example code for docs that are specifically about the `write` method.)

…Sapin

Stablize {f32,f64}::copysign().

Stablization PR for rust-lang#55169/rust-lang#58046. Please check if i'm doing it correctly. Is 1.35.0 good to go?

…=Centril

Fix missed fn rename in rust-lang#59284

See rust-lang#59284 (comment)