[llvm] [IndVarSimplify] Fix Masking Issue by Adding nsw/nuw Flags to Trunc Instruction (PR #150179)

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

Thanks for updating the PR, I'm taking a closer look at it now. In the meantime though is it possible to add any tests to `llvm/test/Transforms/IndVarSimplify/lftr-*.ll` to illustrate the effect of this change more clearly?

https://github.com/llvm/llvm-project/pull/150179