[Bug libstdc++/63776] [C++11] Regex collate matching not working

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63776

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The codecvt stuff was implemented last week. Probably incorrectly, because I
didn't really know what I was doing.