[clang] Reland "[Utils] add update-verify-tests.py" (#108630)" (PR #108658)

[Henrik G. Olsson via cfe-commits]

hnrklssn wrote:

> Hi, `--strip-trailing-cr` isn't a supported option with diff on AIX. Would you be able to adapt the tests?
> 
> https://lab.llvm.org/buildbot/#/builders/64/builds/985

This should fix it: https://github.com/llvm/llvm-project/pull/108871

https://github.com/llvm/llvm-project/pull/108658