[llvm] [AArch64] InsertSelect: Fold both diamond arms into chained CSEL family instructions (PR #212033)

[David Green via llvm-commits]

davemgreen wrote:

It should come up I think? It would be useful to have a test case that shows it running end-to-end. Or is it too complex?

https://github.com/llvm/llvm-project/pull/212033