Test in/out int64 GValue method arguments.
Test in/out int64 GValue method arguments.

See https://bugzilla.gnome.org/show_bug.cgi?id=683596

pexip/pygobject,davibe/pygobject,GNOME/pygobject,pexip/pygobject,davibe/pygobject,sfeltman/pygobject,sfeltman/pygobject,davibe/pygobject,sfeltman/pygobject,davibe/pygobject,pexip/pygobject,GNOME/pygobject,GNOME/pygobject