[llvm] [GlobalISel] Combine away G_UNMERGE(G_IMPLICITDEF). (PR #119183)

[David Green via llvm-commits]

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davemgreen wrote:

I believe zext(undef) was turned into 0, but could then was not folded into the shl/or during the legalizer.

https://github.com/llvm/llvm-project/pull/119183