miri no longer builds after rust-lang/rust#93138

[rust-highfive]

Hello, this is your friendly neighborhood mergebot.
After merging PR #93138, I observed that the tool miri has failing tests.
A follow-up PR to the repository https://github.com/rust-lang/miri is needed to fix the fallout.

cc @matthiaskrgr, do you think you would have time to do the follow-up work?
If so, that would be great!

[nico-abram]

I tried running tests locally against the PR's commit, seems to be failing async-fn and generator. My guess looking at the PRs in the rollup is #91032

This is where it fails on async-fn https://github.com/rust-lang/miri/blob/9983e0fc634e11717eb457a73fe84cfc9409ba8f/tests/run-pass/async-fn.rs#L26-L41

Here's the output:

error: internal compiler error: compiler/rustc_mir_transform/src/generator.rs:755:13: Broken MIR: generator contains type Never in MIR, but typeck only knows about {std::future::ResumeTy, bool, u32, impl std::future::Future<Output = [async output]>, (), impl std::future::Future<Output = [async output]>} and [bool, u32]
  --> $DIR/async-fn.rs:31:53
   |
31 |   async fn includes_never(crash: bool, x: u32) -> u32 {
   |  _____________________________________________________^
32 | |     let mut result = async { x * x }.await;
33 | |     if !crash {
34 | |         return result;
...  |
40 | |     result
41 | | }
   | |_^

[RalfJung]

Yeah the ICE reproduces outside Miri.

[RalfJung]

Filed as separate bug: #93161

[eholk]

I have a small PR at #93165 that should unblock this issue. I'm going to be working on a proper fix today, which I expect will be pretty quick to come up with.

[RalfJung]

Fixed by #93165