[clang] [Clang][AST] Add Test Cases for Reference Qualifiers in Opr Overload (PR #102878)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

> @cor3ntin The solution here #79748 doesn't pass the test too. Kinda expected not to pass the test clang

If tests are not intended to pass, you should expect the diagnostics we issue today, and leave FIXMEs appropriately to indicate where Clang's behavior is wrong.

https://github.com/llvm/llvm-project/pull/102878