[llvm-branch-commits] [clang] [clang] Adjust -pedantic-errors -WX/-Wno-error=X interaction (#184756) (PR #188422)

[Fangrui Song via llvm-branch-commits]

MaskRay wrote:

> I do get the concern though. It would be possible to only backport the fix to make `-pedantic-errors -Wno-error=foo` not error ([a195c71](https://github.com/llvm/llvm-project/commit/a195c719aa96c491ea52bbb8b9e496d2cd6c8445)), and not backport the fix to make `-pedantic-errors -Wfoo` error ([703359d](https://github.com/llvm/llvm-project/commit/703359d44d9a711ac470c15f791328a59d271f4f)). That way we have assurance that the only impact is to _not_ error in cases where Clang 22 currently errors, to reduce the risk, and we could leave that second fix only on LLVM main?

Updated this release/22.x patch to drop the error case.

https://github.com/llvm/llvm-project/pull/188422