Remove unused ownObjectName field from QObjectData

This field isn't used at all in qtbase, nor in any of the qt5
submodules.

Change-Id: If57d389935593f797818506a220c6a3cc04b6078
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/kernel/qobject.h

@@ -100,12 +100,11 @@ public:
     uint blockSig : 1;
     uint wasDeleted : 1;
     uint isDeletingChildren : 1;
-    uint ownObjectName : 1;
     uint sendChildEvents : 1;
     uint receiveChildEvents : 1;
     uint inThreadChangeEvent : 1;
     uint isWindow : 1; //for QWindow
-    uint unused : 22;
+    uint unused : 23;
     int postedEvents;
     QMetaObject *metaObject; // assert dynamic
 };