[clang] [clang] Add nuw attribute to GEPs (PR #105496)

[Vitaly Buka via cfe-commits]

vitalybuka wrote:

This patch breaks:
https://lab.llvm.org/buildbot/#/builders/25/builds/1952
https://lab.llvm.org/buildbot/#/builders/52/builds/1775

https://github.com/llvm/llvm-project/pull/105496