[clang] fixed clang frontend crash with friend class declaration and overload == (PR #133878)

[Younan Zhang via cfe-commits]

https://github.com/zyn0217 commented:

Thanks, this should come with a release entry. Please make sure you add a note to the `Bug Fixes to C++ Support` section in `clang/docs/ReleaseNotes.rst`.

https://github.com/llvm/llvm-project/pull/133878