The code to handle the Enums and Flags type information is automatically built
with `glib-mkenums' and the new templates kept under `build-aux'.
Note: We currently skip the type information of `MMModemBand'. GFlagsValue
can hold only 32-bit types, and we're working with a 64-bit flag here.
See: https://bugzilla.gnome.org/show_bug.cgi?id=663054