[llvm] [ARM]: codegen `llvm.roundeven.v*` (PR #141786)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Hi - thanks for looking into this. I think it will want to generate a vrintn, which is round-to-even. vrintx uses the current rounding mode (and sets inexact flags).

There is an example in https://reviews.llvm.org/D98487, where old llvm.aarch64.neon.frintn intrinsics were upgraded to roundeven.

https://github.com/llvm/llvm-project/pull/141786