[clang] Fix erroneous warning. (PR #79821)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> I don't think we need a Release note for it since this was a faulty behavior to start with. It's not related to any of the options.

Ah, good to know, thanks!

> Would be nice to cherry-pick. Not sure how to do that though.

https://llvm.org/docs/GitHub.html#backporting-fixes-to-the-release-branches

https://github.com/llvm/llvm-project/pull/79821