This makes development on the meta type system easier because only
QtCore must be re-built to run most of the tests. The existing
QGuiVariant test needs to be run before pushing anyway, but not
so frequently.
Change-Id: I1fa66edbd790c957e1a232226847dd550227a477
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@nokia.com>