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

[Ehsan Amiri via llvm-commits]

================

----------------
amehsan wrote:

> So the conclusion is to finish each approach, correct?

 Yes. Let's write down two independent proposals. So that other people can read and compare them. Let's create two separate issue and make sure they are self-contained so everyone can read them independent of previous discussions

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