Filter out `ProcMacroStub`s to avoid an ICE during cleaning.

Also add proc macros to `cache().paths` so it can generate links.

This shrinks `Option<Symbol>` from 8 bytes to 4 bytes, which shrinks
`Token` from 24 bytes to 16 bytes. This reduces instruction counts by up
to 1% across a range of benchmarks.

…t-lang/libc#1057.

Part of issue rust-lang#55465

Requested in rust-lang/stdarch#322 this is hopefully the first
step!

gdb versions before 8.1 have a bug that prevents the BTreeSet and
BTreeMap pretty-printers from working.  This patch disables the test
on those versions, and also disables the pretty-printers there as
well.

Closes rust-lang#56730

This is going to be required for binding a number of AVX-512 intrinsics
in the `stdsimd` repository, and this intrinsic is the same as
`simd_select` except that it takes a bitmask as the first argument
instead of a SIMD vector. This bitmask is then transmuted into a `<NN x
i8>` argument, depending on how many bits it is.

cc rust-lang/stdarch#310

Esteban Kuber requested that the panic message make it clear
that `RUST_BACKTRACE=1` is an environment variable.  This change
makes that clear.  Wording provided in part by David Tolnay.

…et-cpu-attr, r=alexcrichton

Unconditionally emit the target-cpu LLVM attribute.

This PR makes `rustc` always emit the `target-cpu` LLVM attribute for functions. The goal is to allow for cross-language inlining of functions defined in `libstd`. So far `libstd` functions were the only function without a `target-cpu` attribute, so in whole-crate-graph cross-lang LTO scenarios they were not eligible for inlining into foreign code.

r? @alexcrichton

…export, r=QuietMisdreavus

rustdoc: Fix local reexports of proc macros

Filter out `ProcMacroStub`s to avoid an ICE during cleaning.

Also add proc macros to `cache().paths` so it can generate links.

r? @QuietMisdreavus

…r=petrochenkov

Add non-panicking `maybe_new_parser_from_file` variant

Add (seemingly?) missing `maybe_new_parser_from_file` constructor variant.

Disclaimer: I'm not certain this is the correct approach - just found out we don't have this when working on a Rustfmt PR to catch/prevent more Rust parser panics: rust-lang/rustfmt#3240 and tried to make it work somehow.

…bank

Fix irrefutable matches on integer ranges

Fixes rust-lang#56659.

Use a `newtype_index!` within `Symbol`.

This shrinks `Option<Symbol>` from 8 bytes to 4 bytes, which shrinks
`Token` from 24 bytes to 16 bytes. This reduces instruction counts by up
to 1% across a range of benchmarks.

r? @oli-obk

…r=michaelwoerister

[self-profiler] Add column for percent of total time

Example output:

```
Self profiling results:

| Phase            | Time (ms)      | Time (%) | Queries        | Hits (%)
| ---------------- | -------------- | -------- | -------------- | --------
| Parsing          | 3              | 0.52     |                |
| Expansion        | 64             | 11.27    |                |
| TypeChecking     | 13             | 2.36     | 35208          | 90.77
| BorrowChecking   | 0              | 0.10     | 68             | 50.00
| Codegen          | 22             | 3.82     | 7362           | 75.12
| Linking          | 252            | 43.81    | 458            | 68.56
| Other            | 219            | 38.12    | 47372          | 56.84

Optimization level: No
Incremental: off

```

cc @michaelwoerister

…, r=alexcrichton

Remove some unnecessary feature gates

fixes rust-lang#56585

cc @jethrogb

… r=QuietMisdreavus

Remove unneeded extra chars to reduce search-index size

Before:

```
2013782 Dec 11 10:16 build/x86_64-unknown-linux-gnu/doc/search-index.js
```

After:

```
1736597 Dec 11 10:50 build/x86_64-unknown-linux-gnu/doc/search-index.js
```

No changes in the output of the search.

r? @QuietMisdreavus

…wjasper

specialize: remove Boxes used by Children::insert

Update panic message to be clearer about env-vars

Esteban Kuber requested that the panic message make it clear
that `RUST_BACKTRACE=1` is an environment variable.  This change
makes that clear.

I understand that this may simply be closed if the concept isn't accepted, and I'd be fine with that :-)

Fixes rust-lang#56734

x86: Add the `adx` target feature to whitelist

Requested in rust-lang/stdarch#322 this is hopefully the first
step!

…er, r=alexcrichton

Disable btree pretty-printers on older gdbs

gdb versions before 8.1 have a bug that prevents the BTreeSet and
BTreeMap pretty-printers from working.  This patch disables the test
on those versions, and also disables the pretty-printers there as
well.

Closes rust-lang#56730

…=rkruppe

rustc: Add an unstable `simd_select_bitmask` intrinsic

This is going to be required for binding a number of AVX-512 intrinsics
in the `stdsimd` repository, and this intrinsic is the same as
`simd_select` except that it takes a bitmask as the first argument
instead of a SIMD vector. This bitmask is then transmuted into a `<NN x
i8>` argument, depending on how many bits it is.

cc rust-lang/stdarch#310

…rsion, r=alexcrichton

Update libc version required by rustc

This is meant to be an easy-to-backport fix for rust-lang#55465