[llvm] [AArch64] treat `@llvm.ssub.sat` the same as `@llvm.aarch64.neon.sqsub` (PR #140454)

[Folkert de Vries via llvm-commits]

folkertdev wrote:

I think this PR is ready to merge?

Thanks for all the help here btw!

https://github.com/llvm/llvm-project/pull/140454