[clang] Revert "[clang] Add nuw attribute to GEPs" (PR #106343)

[via cfe-commits]

zmodem wrote:

> > Please let me know if you have a fix for that. I'll land revert in the morning by PDT.
> 
> Thank you for flagging this up and opening this @vitalybuka - I'm taking a look now to see if there's an easy enough fix to save reverting.

No need to save reverting --- reverting faster is better since it takes the pressure off while investigating, and saves more people from hitting this issue.

https://github.com/llvm/llvm-project/pull/106343