The test uses QDeclarativePlaylist, but no out-of-line methods or data members, so it got by with just including the header. But a ubsan build requires access to the class' typeinfo objects, so add QDeclarativePlaylist's implementation to the test, too. Change-Id: Ib6bb155b71c0082969f77a13a0e50132a782db2d Reviewed-by: Yoann Lopes <yoann.lopes@theqtcompany.com>