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

[David Green via cfe-commits]

davemgreen wrote:

> This intrinsic is only a month old so adding an auto upgrade might be an overkill. What do you think ?

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.

> Current implementation of __arm_atomic_store_with_stshh is incorrect as it doesn't enforce the memory ordering constraints as can be seen [here](https://godbolt.org/z/n5YnbaT8E).

Why not just fix the bug though? If the bug is "llvm cannot represent atomic intrinsics" then I would be surprised, but it sound like something that is worth supporting. If the real problem is a complex and subtle issue to do with capture tracking of function local / noalias arguments on what looks like any call instructions - then can we fix that directly instead?

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