[clang] Carving out -Wformat warning about scoped enums into a subwarning (PR #88595)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

Please be sure to add a release note in clang/docs/ReleaseNotes.rst. The code changes themselves LGTM, but there are some issues with the tests.

https://github.com/llvm/llvm-project/pull/88595