[clang] [clang][diagnostics] added warning for possible enum compare typo (PR #168445)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

Thanks! You should also add a release note to `clang/docs/ReleaseNotes.rst` so users know about the improved diagnostic.

https://github.com/llvm/llvm-project/pull/168445