Issue description

The C.UTF-8 locale is missing (locale -a). We do have lots of other UTF-8 locales, but those are all country specific.

• https://sourceware.org/glibc/wiki/Proposals/C.UTF-8
• https://lists.fedoraproject.org/pipermail/glibc/2015-September/000081.html