rustc_target: aarch64: Remove deprecated FEAT_TME

[maurer]

ARM has withdrawn FEAT_TME

https://developer.arm.com/documentation/102105/lb-05/

LLVM has dropped support for generating it
llvm/llvm-project#167687

@rustbot label llvm-main

r? @durin42

[workingjubilee]

The feature being "stable" while the intrinsics are not effectively means we should only continue recognizing the name and not emit an error or warning when someone passes it, that's all. I don't think we have to even try to do codegen for it.

[mysterymath]

Hey! This is currently blocking the Rust roll into the Fuchsia project's toolchain, and we'd expect that other open source projects that track Rust/LLVM at head are similarly blocked. Can we get the workaround mentioned above landed quickly? I can spare time to help with this, but I'm not tremendously familiar with rustc as of yet.

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[rustbot]

⚠️ Warning ⚠️

• The following commits have merge commits (commits with multiple parents) in your changes. We have a no merge policy so these commits will need to be removed for this pull request to be merged.

  • 2788686
  • 2922cbd
  • 485ea04
  • 57436fe
  • 5914877
  • 7f3fcb3
  • 849ace0
  • 84c44c4
  • 8dc0761
  • b851387
  • c610b1d
  • d84c695
  • ff78b84

  You can start a rebase with the following commands:

  $ # rebase
  $ git pull --rebase https://github.com/rust-lang/rust.git main
  $ git push --force-with-lease
  

[maurer]

@rustbot ready

I've made the requested change, and put it on top of a josh-sync of stdarch rather than editing stdarch directly. rustbot seems upset that josh generates merge commits, so perhaps I've done that step wrong. If someone either wants to point me to what I did wrong in trying to sync stdarch back or to update it themselves, I'll rebase, but this commit should match what was requested now.

[maurer]

@rustbot author

Waiting on landing stdarch update in rustc.

[sayantn]

Am I missing something obvious? How do other people deal with this?

The rustbot message on modifying stdarch is just advice; if you are actually editing rustc and stdarch together (without a reasonable way to decouple the changes), it is best to just do them simply (after all this was the motivation behind migrating to josh from submodules). You don't need to do the josh-sync at all (that's independent of this PR).

[folkertdev]

What's causing us grief here really is that this repository does not (yet) run the stdarch tests. If it did, we could make changes to stdarch with more confidence in this repository. So for the time being, complex changes that touch both need this synchronization dance, thankfully that is quite rare.

I'm sure the josh stuff is better than the alternatives, but I fully agree that it is not very user-friendly, and its errors are unhelpful to normal users.