[llvm] [InstCombine] Drop noundef attributes in `foldCttzCtlz` (PR #116718)

[Nikita Popov via llvm-commits]

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

LGTM, though I'd also consider not doing in-place modification here and just creating a new call. Generally we should probably stop doing in-place modification where possible, it always only causes issues.

https://github.com/llvm/llvm-project/pull/116718