[libcxx] adds concept `std::common_reference_with`

Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96657

Reviewed By: ldionne, Mordante, #libc

Differential Revision: https://reviews.llvm.org/D96660

GitOrigin-RevId: 3f5438c46cc8ddfbd221336153700da0bc527752
2 files changed