Make it possible to define G_LOG_DOMAIN multiple times in a project
I would be very interested to define it for a whole .vala file as it is already possible in C (see how it is done in GNOME Builder https://gitlab.gnome.org/GNOME/gnome-builder/blob/master/src/libide/core/ide-context-addin.c#L21 that makes it easier to debug afterwards)