Add an assert simplifying debugging.

Statics should not be deleted, the assert shows a nicer debug
information then a segmentation fault.

Change-Id: I9eedbfa966d7865fd7bb1e130c79e40bae3526cb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qarraydata.cpp

@@ -112,6 +112,7 @@ void QArrayData::deallocate(QArrayData *data, size_t objectSize,
     if (data == &qt_array_unsharable_empty)
         return;
 
+    Q_ASSERT_X(!data->ref.isStatic(), "QArrayData::deallocate", "Static data can not be deleted");
     ::free(data);
 }