[llvm] [Intrinsics][AArch64] Add intrinsic to mask off aliasing vector lanes (PR #117007)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

> FYI: I recall there was a recent discussion where the conclusion was to do away with the `experimental` naming for new intrinsics because it doesn't really mean anything and just causes more work down the line.

Yes, the post is: https://discourse.llvm.org/t/rfc-dont-use-llvm-experimental-intrinsics/85352

https://github.com/llvm/llvm-project/pull/117007