Fix `rustc_codegen_gcc` build and tests failure in CI
https://github.com/rust-lang/rust/pull/118463 seems to have broke the PR CI, more specificaly the `x86_64-gnu-llvm-16` builder which [fail with](https://github.com/rust-lang/rust/actions/runs/7128709674/job/19411205695?pr=118705#step:26:1668):
```
Building stage1 codegen backend gcc (x86_64-unknown-linux-gnu)
Compiling libc v0.2.147
Compiling rustix v0.38.8
Compiling memchr v2.5.0
Compiling bitflags v2.4.0
Compiling linux-raw-sys v0.4.5
Compiling fastrand v2.0.0
Compiling smallvec v1.10.0
error: invalid `--check-cfg` argument: `values(freebsd10)` (expected `cfg(name, values("value1", "value2", ... "valueN"))`)
error: could not compile `libc` (lib) due to previous error
```
Updating to `libc` version 0.2.150 fixes the build issue since it includes the support for the new check-cfg syntax.
Then it [failed](https://github.com/rust-lang/rust/actions/runs/7129280743/job/19413025132?pr=118706#step:26:2218) with a missing `#![allow(internal_features)]` in one of the example.
r? `@GuillaumeGomez`
These files were added to the repository but never wired up so they could
be used - and that was a few years ago without anyone noticing - so let's
remove these, they can be re-added if someone wants them.
Signed-off-by: David Wood <david@davidtw.co>
Re-enable `rustc_codegen_gcc` tests in CI
When #117947 dropped llvm-15 from CI, we neglected to copy #117313's changes to enable `rustc_codegen_gcc` testing to the new base llvm-16. This is now restored, as well as copying the setup to llvm-17 as well so we hopefully won't miss it next time.
In addition, due to case mismatch in `$extra_env` updates in `docker/run.sh`, I think it wasn't actually getting enabled before, but this should now be fixed. I also avoided the linker hack for `libgccjit.so` that was present before, because that's not needed if the version matches the base `gcc` used for linking.
r? GuillaumeGomez
`EvaluatedToUnknown` -> `EvaluatedToAmbigStackDependent`, `EvaluatedToRecur` -> `EvaluatedToErrStackDependent`
Less confusing names, since the only difference between them and their parallel `EvalutedTo..` is that they are stack dependent.
r? lcnr
Remove `PolyGenSig` since it's always a dummy binder
Coroutines are never polymorphic in their signature. This cleans up a FIXME in the code:
```
/// Returns the "coroutine signature", which consists of its yield
/// and return types.
///
/// N.B., some bits of the code prefers to see this wrapped in a
/// binder, but it never contains bound regions. Probably this
/// function should be removed.
```
Fix is_foreign_item for StableMIR instance
Change the implementation of `Instance::is_foreign_item` to directly query the compiler for the instance `def_id` instead of incorrectly relying on the conversion to `CrateItem`. I also added a method to check if the instance has body, since the function already existed and it just wasn't exposed via public APIs. This makes it much cheaper for the user to check if the instance has body.
## Background:
- In pull https://github.com/rust-lang/rust/pull/118524, I fixed the conversion from Instance to CrateItem to avoid the conversion if the instance didn't have a body available. This broke the `is_foreign_item`.
r? `@ouz-a`
rustc_arena: add `alloc_str`
Two places called `from_utf8_unchecked` for strings from `alloc_slice`,
and one's SAFETY comment said this was for lack of `alloc_str` -- so
let's just add that instead!
Enforce `must_use` on associated types and RPITITs that have a must-use trait in bounds
Warn when an RPITIT or (un-normalized) associated type with a `#[must_use]` trait in its bounds is unused.
This is pending T-lang approval, since it changes the semantics of the `#[must_use]` attribute slightly, but I think it strictly catches more strange errors.
I could also limit this to just RPITITs, but that seems less useful.
Fixes#118444
tip for define macro name after `macro_rules!`
Fixes#118295
~Note that there are some bad case such as `macro_rules![]` or `macro_rules!()`. However, I think these are acceptable as they are likely to be seldom used (feel free to close this if you think its shortcomings outweigh its benefits)~
Edit: this problem was resolved by utilizing the `source_map.span_to_next_source`.
r? `@petrochenkov`
Suppress warnings in LLVM wrapper when targeting MSVC
The LLVM header files generate many warnings when compiled using MSVC. This makes it difficult to work on the LLVM wrapper code, because the warnings and errors that are relevant to local edits are obscured by the hundreds of lines of warnings from the LLVM Headers.
Use the glob binding in resolve_rustdoc_path process
Fixes#117920
Returning `None` seems enough.
I reproduces and tests this locally by `cargo +stage1 build`, but I cannot reproduce this ICE by putting [the following code](https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=8b3ca8f4a7676eb90baf30437ba041a2) into `tests/ui/...` and then compiling it using `rustc +stage1 /path/to/test.rs` or `x.py test`:
```rust
#![crate_type = "lib"]
use super::Hasher;
/// [`Hasher`]
pub use core:#️⃣:*;
```
r? `@petrochenkov`
