[llvm] [AArch64] Create set.fpmr intrinsic and assembly lowering (PR #114248)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Can you explain how these are intended to be used? I am maybe a bit out of touch but I was under the impression that the FP8 intrinsics had fpmr operands to make data-flow analysis possible. Does a stand-along intrinsic not go against that?

https://github.com/llvm/llvm-project/pull/114248