[Bug libstdc++/106749] Implement C++23 library features

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106749
Bug 106749 depends on bug 122946, which changed state.

Bug 122946 Summary: [C++20 DR] Implement P2404R3, Move-only types for equality_comparable_with, totally_ordered_with, and three_way_comparable_with
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122946

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED