[clang] Make warning pragma override -Werror=foo and DefaultError warnings (PR #93647)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

Thank you for this! Please add a release note to clang/docs/ReleaseNotes.rst so users know about the behavioral change. Also, should we update some documentation as well?

https://github.com/llvm/llvm-project/pull/93647