it is in the libcs' crate too now.

Add `E0796` error code.
Add `static_mut_ref` lint.

This is the idea for the 2024 edition.

…port

Map is implemented as a pointer to a mutable object.
Rustdoc never mutates function signatures after constructing them,
but the JS engine doesn't know that.

To save a bunch of memory, use a single immutable map
for every decoded type object with no bindings or generics.

It was added in rust-lang#54232. It seems like it was aimed at NLL development,
which is well in the past. Also, it looks like `-Ztreat-err-as-bug` can
be used to achieve the same effect. So it doesn't seem necessary.

This takes advantage of more reuse opportunities.
Along with the empty object commit, they
bringing memory usage down about 20% over the original.

LLVM 11 has been unsupported since 4559140,
so this doesn't need to be conditional on the LLVM version.

…twco

Disallow reference to `static mut` and adding `static_mut_ref` lint

Closes rust-lang#114447

r? `@scottmcm`

…ilstrieb,dtolnay

std: getrandom simplification for freebsd.

it is in the libcs' crate too now.

…c, r=JohnTitor

Rework and improve the unstable documentation of check-cfg

This PR rework and improve the unstable documentation of the check-cfg feature.

The goal is to have a simpler to understand documentation with examples that are more practical and less theoretical. As well as making the documentation more explicit about the whereabouts of the feature.

`@rustbot` label  T-compiler  F-check-cfg

don't reexport atomic::ordering via rustc_data_structures, use std import

This looks simpler.

Simplify implementation of MIR promotion

Non-functional changes.
Best read ignoring whitespace.

…li-obk

Merge dead bb pruning and unreachable bb deduplication.

Both routines share the same basic structure: iterate on all bbs to identify work, and then renumber bbs.

We can do both at once.

…stics, r=compiler-errors

Remove `-Zdont-buffer-diagnostics`.

It was added in rust-lang#54232. It seems like it was aimed at NLL development, which is well in the past. Also, it looks like `-Ztreat-err-as-bug` can be used to achieve the same effect. So it doesn't seem necessary.

r? ``@pnkfelix``

…uillaumeGomez

rustdoc-search: reuse individual types in function signatures

Because `search.js` never mutates the function signature after loading it,
they can be safely and easily reused across functions.

This change doesn't change the format of the search index.
It only changes `search.js`.

Profiler output: https://notriddle.com/rustdoc-html-demo-9/fn-signature-opti2/index.html

<table><tr><th>benchmark<th>before<th>after

<tr><th>arti<td>

```
user: 002.228 s
sys:  000.315 s
wall: 001.663 s
child_RSS_high:     315668 KiB
group_mem_high:     288638 KiB
```

<td>

```
user: 001.805 s
sys:  000.231 s
wall: 001.398 s
child_RSS_high:     235864 KiB
group_mem_high:     203056 KiB
```

<tr><th>cortex-m<td>

```
user: 000.143 s
sys:  000.035 s
wall: 000.140 s
child_RSS_high:      59168 KiB
group_mem_high:      23000 KiB
```

<td>

```
user: 000.138 s
sys:  000.031 s
wall: 000.133 s
child_RSS_high:      58944 KiB
group_mem_high:      22220 KiB
```

<tr><th>sqlx<td>

```
user: 000.792 s
sys:  000.115 s
wall: 000.536 s
child_RSS_high:     156716 KiB
group_mem_high:     122948 KiB
```

<td>

```
user: 000.824 s
sys:  000.084 s
wall: 000.535 s
child_RSS_high:     136668 KiB
group_mem_high:     101792 KiB
```

<tr><th>stm32f4<td>

```
user: 006.665 s
sys:  003.533 s
wall: 008.624 s
child_RSS_high:    1037660 KiB
group_mem_high:    1022516 KiB
```

<td>

```
user: 005.997 s
sys:  003.185 s
wall: 007.987 s
child_RSS_high:     832068 KiB
group_mem_high:     810908 KiB
```

<tr><th>stm32f4xx-hal<td>

```
user: 000.317 s
sys:  000.051 s
wall: 000.203 s
child_RSS_high:      77060 KiB
group_mem_high:      41776 KiB
```

<td>

```
user: 000.287 s
sys:  000.046 s
wall: 000.180 s
child_RSS_high:      75216 KiB
group_mem_high:      39200 KiB
```

<tr><th>ripgrep<td>

```
user: 000.463 s
sys:  000.063 s
wall: 000.295 s
child_RSS_high:     101288 KiB
group_mem_high:      66364 KiB
```

<td>

```
user: 000.472 s
sys:  000.036 s
wall: 000.247 s
child_RSS_high:      82708 KiB
group_mem_high:      47056 KiB
```

</tr></table>

GNU/Hurd: unconditionally use inline stack probes

LLVM 11 has been unsupported since 4559140, so this doesn't need to be conditional on the LLVM version.

cc `@sthibaul`