[llvm] [InstSimplify] Handle nsz when simplifying X * 0.0 (PR #142181)

[Alex MacLean via llvm-commits]

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

LGTM but this is not an area I work on regularly so please wait for other reviewers more familiar with this pass to land. 

https://github.com/llvm/llvm-project/pull/142181