Split phase change from `MirPass`
The main goal here is to simplify the pass manager logic. `MirPass` no longer contains the `phase_change` method, and `run_passes` instead accepts an `Option<PhaseChange>`. The hope is that this addresses the comments (and maybe perf regression) from #99102 .
r? `@oli-obk` cc `@RalfJung`
This allows writing the following function signatures:
```rust
fn f0() -> impl Fn() -> impl Trait;
fn f3() -> &'static dyn Fn() -> impl Trait;
```
These signatures were already allowed for common traits and associated
types, there is no reason why `Fn*` traits should be special in this
regard.
update Miri
I had to use a hacked version of josh to create this, so let's be careful with merging this and maybe wait a bit to see if the josh issue becomes more clear. But the history looks good to me, we are not adding duplicates of rustc commits that were previously mirrored to Miri.
Also I want to add some cross-testing of Miri in x.py.
Truncate thread names on Linux and Apple targets
These targets have system limits on the thread names, 16 and 64 bytes
respectively, and `pthread_setname_np` returns an error if the name is
longer. However, we're not in a context that can propagate errors when
we call this, and we used to implicitly truncate on Linux with `prctl`,
so now we manually truncate these names ahead of time.
r? ``````@thomcc``````
rustc: Use `unix_sigpipe` instead of `rustc_driver::set_sigpipe_handler`
This is the first (known) step towards starting to use `unix_sigpipe` in the wild. Eventually, `rustc_driver::set_sigpipe_handler` can be removed and all clients can use `unix_sigpipe` instead.
For now we just start using `unix_sigpipe` in one place: `rustc` itself.
It is easy to manually verify this change. If you remove `#[unix_sigpipe = "sig_dfl"]` and run `./x.py build` you will get an ICE when you do `./build/x86_64-unknown-linux-gnu/stage1/bin/rustc --help | false`. Add back `#[unix_sigpipe = "sig_dfl"]` and the ICE disappears again.
PR that added `set_sigpipe_handler`: https://github.com/rust-lang/rust/pull/49606
Tracking issue for `unix_sigpipe`: #97889
Not sure exactly how to label this PR. Going with T-libs for now since this is a T-libs feature.
````@rustdoc```` labels +T-libs
Before this commit, compiletest would add `-L path/to/aux` at the end of
the rustc flags, even after the custom ones set with the compile-flags
header comment. This made it impossible to check how rustc would behave
when a flag requiring an argument was passed without the argument,
because the argument would become `-L`.
This PR fixes that by adding the `-L path/to/aux` before the arguments
defined in compile-flags, at least for UI tests. Other test suites might
either be fixed as well by this change, or still present the old
behavior.
