[llvm] [InstCombine] Fold integer unpack/repack patterns through ZExt (PR #153583)

[Yingwei Zheng via llvm-commits]

https://github.com/dtcxzyw approved this pull request.

LGTM. Please rebase this patch on top of https://github.com/llvm/llvm-project/pull/153692 and use `m_ConstantInt`.

https://github.com/llvm/llvm-project/pull/153583