[llvm] [InstCombine] Do not perform binop-of-shuffle when mask is poison (PR #82185)

[via llvm-commits]

goldsteinn wrote:

It looks like only your third test is problematic: https://alive2.llvm.org/ce/z/WrH49f
can the fix be made more precise?

https://github.com/llvm/llvm-project/pull/82185