glib-mkenums is not currently clever enough to know which version an
enum type was added in, so just mark all the _get_type() functions as
available in all versions.
https://bugzilla.gnome.org/show_bug.cgi?id=688681
/*** END file-production ***/
/*** BEGIN value-header ***/
-GType @enum_name@_get_type (void) G_GNUC_CONST;
+GLIB_AVAILABLE_IN_ALL GType @enum_name@_get_type (void) G_GNUC_CONST;
#define @ENUMPREFIX@_TYPE_@ENUMSHORT@ (@enum_name@_get_type ())
/*** END value-header ***/