[llvm] [DA] Infer nsw on validated fixed-size delinearized subscripts (PR #201882)

[Madhur Amilkanthwar via llvm-commits]

madhur13490 wrote:

> It's possible that this old patch I have lying around would help: [987117f](https://github.com/llvm/llvm-project/commit/987117fd7ae9aef83e1551faa8c8cd0a96a2c90a)
> 
> Edit: Rebased [nikic at 7ee4d53](https://github.com/nikic/llvm-project/commit/7ee4d53f135dbc94022b89be89723e49ae75e555)

I just cherry-picked it on my branch and disabled my fix, and this helps; the loop is interchanged. @nikic, if you are planning to take it ahead, I can close this MR. Otherwise, I am also open to take your patch ahead with some cleanup?

https://github.com/llvm/llvm-project/pull/201882