[llvm] [VectorCombine] Fold Deinterleave/Interleave Pairs (PR #211022)

[Benjamin Maxwell via llvm-commits]

================

----------------
MacDue wrote:

Is the `IsConvergent` check necessary? I would not expect any trivially vectorizable intrinsic to hit this (also untested).  

https://github.com/llvm/llvm-project/pull/211022