[llvm] [AArch64] Add combine for interleave deinterleave (3/n) (PR #208414)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

Sorry for the delay - I was looking into fixes with the release. Can this be rebased away from the other patches (even if it's not quite optimal). I think it looks OK if so.

https://github.com/llvm/llvm-project/pull/208414