During the review of https://reviews.llvm.org/D93912 we failed to notice the implementation status wasn't updated. This rectifies the issue.
* https://wg21.link/p1048 Reviewed By: ldionne, #libc Differential Revision: https://reviews.llvm.org/D94409
Also: * Fix header line in all status tables. * Use C++20 instead of C++2a. Reviewed By: ldionne, #libc, miscco Differential Revision: https://reviews.llvm.org/D92306