[llvm] [LegalizeDAG] Optimize CodeGen for `ISD::CTLZ_ZERO_UNDEF` (PR #83039)

[Manish Kausik H via llvm-commits]

Nirhar wrote:

I do not understand why the CI failed here: https://buildkite.com/llvm-project/github-pull-requests/builds/76944#019068e3-bd93-4ad9-ba55-817fdabbe0eb. Looks like all the tests passed

https://github.com/llvm/llvm-project/pull/83039