…r=oli-obk

Add regression test for issue rust-lang#79865

Closes rust-lang#79865

Correct codegen of `ConstValue::Indirect` scalar and scalar pair

This concerns 3 tricky cases with `ConstValue::Indirect`:
- if we want a non-pointer scalar;
- if we have non-zero offset;
- if offset points to uninit memory => generate `poison` instead of an ICE. This case could happen in unreachable code, trying to extract a field from the wrong variant.

Those cases are not currently emitted by the compiler, but are exercised by rust-lang#116012.

Rename `cold_path` to `outline`

I find this name to be a bit more descriptive.

r? `@oli-obk`

subst -> instantiate

continues rust-lang#110793, there are still quite a few uses of `subst` and `substitute`, but changing them all in the same PR was a bit too much, so I've stopped here for now.

…=fmease

Fix typo in rustdoc unstable features doc

Update books

## rust-embedded/book

1 commits in 99ad2847b865e96d8ae7b333d3ee96963557e621..eac173690b8cc99094e1d88bd49dd61127fbd285
2023-09-12 07:34:44 UTC to 2023-09-12 07:34:44 UTC

- USB connector-type correction (rust-embedded/book#360)

## rust-lang/nomicon

1 commits in e3f3af69dce71cd37a785bccb7e58449197d940c..ddfa4214487686e91b21aa29afb972c08a8f0d5b
2023-09-22 17:04:10 UTC to 2023-09-22 17:04:10 UTC

- Fill "Beneath `std`" (rust-lang/nomicon#413)

## rust-lang/reference

1 commits in ee7c676fd6e287459cb407337652412c990686c0..5262e1c3b43a2c489df8f6717683a44c7a2260fd
2023-09-18 18:28:31 UTC to 2023-09-18 18:28:31 UTC

- we reserve the right to reduce our amount of UB (rust-lang/reference#1397)

## rust-lang/rustc-dev-guide

8 commits in 08bb147d51e815b96e8db7ba4cf870f201c11ff8..a13b7c28ed705891c681ce5417b3d1cdb12cecd1
2023-09-25 05:14:41 UTC to 2023-09-11 21:29:18 UTC

- Clarify all the `{AP,RP}IT{,IT}` impl trait types (rust-lang/rustc-dev-guide#1798)
- Modify build instructions for optimized build (rust-lang/rustc-dev-guide#1795)
- Remove outdated references to coverage debug code (rust-lang/rustc-dev-guide#1797)
- Add deep dive document about early/late bound parameters interacting with turbofish (rust-lang/rustc-dev-guide#1794)
- explain the MIR const vs TY const situation (rust-lang/rustc-dev-guide#1793)
- fix type name (rust-lang/rustc-dev-guide#1792)
- Clarify that `run-coverage` only runs in some of the CI jobs (rust-lang/rustc-dev-guide#1791)
- Document the `coverage-map` and `run-coverage` test suites (rust-lang/rustc-dev-guide#1790)

…intrinsic, r=Nilstrieb

Gate and validate `#[rustc_safe_intrinsic]`

Copied over from rust-lang#116159:

> This was added as ungated in https://github.com/rust-lang/rust/pull/100719/files#diff-09c366d3ad3ec9a42125253b610ca83cad6b156aa2a723f6c7e83eddef7b1e8fR502, probably because the author looked at the surrounding attributes, which are ungated because they are gated specially behind the staged_api feature.
>
> I don't think we need to crater this, the attribute is entirely useless without the intrinsics feature, which is already unstable..

r? `@Nilstrieb`