[llvm] [InstCombine] Fold zext into de-interleaving (factor=2) instructions (PR #195330)

[Min-Yih Hsu via llvm-commits]

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mshockwave wrote:

@davemgreen could you help me to review the change here? I tried to see the difference on the codegen but llc somehow crashed on other functions in the optimized version of this file. 

https://github.com/llvm/llvm-project/pull/195330