[llvm] [DA] Add tests for nsw doesn't hold on entier iteration (PR #162281)

[Ehsan Amiri via llvm-commits]

amehsan wrote:

It would be great to have the opinion of llvm area team about this discussion. @nikic @arsenm @fhahn 

I don't know what is your approach, but my suggestion is to start with a meeting on the issue. Obviously feel free to ignore my suggestion as I am not familiar with your processes.

https://github.com/llvm/llvm-project/pull/162281