Earlier in the C++26 cycle, we opted to deprecate the facets:
   codecvt<char16_t, char8_t, mbstate_t>
   codecvt<char32_t, char8_t, mbstate_t>
   codecvt_byname<char16_t, char8_t, mbstate_t>
   codecvt_byname<char32_t, char8_t, mbstate_t>


Now we have agreed to remove the previously deprecated facets:
   codecvt<char16_t, char, mbstate_t>
   codecvt<char32_t, char, mbstate_t>
   codecvt_byname<char16_t, char, mbstate_t>
   codecvt_byname<char32_t, char, mbstate_t>

Should we consider removing all these facets in one hit?
It would seem a nice way to clear the decks for whatever
Unicode support we plan to develop for C++29.

At this stage, removal would mean filing an NB comment once
the CD goes out to ballot, and I would not be prepared to write
such a comment unless this group were already in favor.

AlisdairM