[clang] [llvm] Remove __arm_atomic_store_with_stshh from llvm (PR #192419)

[via cfe-commits]

Lukacma wrote:

> llvm cannot represent atomic intrinsics

Yeah that's exactly the bug from what I understand. Of course it will be good to fix,  as this effects other builtins like __builtin_arm_stlex, but currently this is not priority for us. We are also redisigning the ACLE for this builtin and we plan to implement it as an atomic store with metadata, so most of it will need to be redone anyway. We are removing it for now to reduce the amount of wrong code being generated.

> If they were not in the last release (I believe they were not unless they were added after the version on godbolt), then we can avoid it.

I think this builtin would be in LLVM 22.1.2 onwards. I don't know how the policy works for minor releases regarding this ?

https://github.com/llvm/llvm-project/pull/192419