Thanks for pinging. I think we just need to go with the previous
__STDC_ISO_10646__ macro value for now until there's a new one. I
don't think it's a conformance problem to support additional new
characters we don't advertise support for with the macro, so it's not
a big deal. I can add it as a separate commit and update later with
another once there's a new value to be used.

BTW are there any new case mappings needed too? I can handle those if
so. (The current case mapping code needs manual work to update; I have
a draft replacement that won't need manual work I should really get
around to integrating.)