[clang] [clang] Bugfix for choosing the more specialized overload (PR #83279)

[Botond István Horváth via cfe-commits]

HoBoIs wrote:

> DR changes looks good now, save for a nitpick. However, I'm leaving it to other reviewers to check contents of the test. It looks like an example from the DR, but I don't feel qualified to say whether this test has sufficient coverage.

I have added tests to other files what are relevant for the DR too. Should I move them here?

https://github.com/llvm/llvm-project/pull/83279