[clang] [Sema] Use underlying type of scoped enum for -Wformat diagnostics (PR #67378)

[Christopher Di Bella via cfe-commits]

https://github.com/cjdb commented:

Thanks for working on this, it seems like an important fix. Would you mind updating the release notes please? I'll approve afterwards.

https://github.com/llvm/llvm-project/pull/67378