[llvm] [AArch64] Mark neon.stN intrinsics as writeonly (PR #145289)

[Nikita Popov via llvm-commits]

nikic wrote:

> I don't know of a reason why this would be a problem. The MVE intrinsics already specify IntrWriteMem. Should we add it to the similar Arm neon intrinsics too, either here or in a followup?

I've added the Arm variants now as well.

https://github.com/llvm/llvm-project/pull/145289