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

[Ryotaro Kasuga via llvm-commits]

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kasuga-fj wrote:

I'll ask again. Do you have no intention of retracting the "Request changes"? I still feel you are using this button just because "I don't like this" or "I don't understand this". I believe it should not be used in this way. (To be clear, I'm not asking you to approve the PR. I just feel this is blocking the progress of this PR unnecessarily.)

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