[REG 5.8.0 -> 5.9.0 Beta 1] Designer crashes

1. Build Creator on Qt 5.9 beta 1.
2. Run Creator with default settings, e.g. by passing the parameter -settingspath <empty directory>.
3. Open a qml-file.
4. Go to Design mode.
   Creator crashes:

   1   QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e49ee0a 
   2   QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e4950fb 
   3   QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e49ed93 
   4   QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e7a4a20 
   5   QmlDesigner::StatesEditorWidget::setCurrentStateInternalId                                                                                  stateseditorwidget.cpp 68   0x580528a6 
   6   QmlDesigner::StatesEditorView::resetModel                                                                                                   stateseditorview.cpp   172  0x58056dba 
   7   QmlDesigner::StatesEditorView::modelAttached                                                                                                stateseditorview.cpp   318  0x58055651 
   8   QmlDesigner::Internal::ModelPrivate::attachView                                                                                             model.cpp              873  0x57ef592e 
   9   QmlDesigner::Model::attachView                                                                                                              model.cpp              2040 0x57ef3c81 
   10  QmlDesigner::ViewManager::attachViewsExceptRewriterAndComponetView                                                                          viewmanager.cpp        278  0x57f75c39 
   11  QmlDesigner::QmlDesignerPlugin::activateAutoSynchronization                                                                                 qmldesignerplugin.cpp  406  0x57e366a0 
   12  QmlDesigner::QmlDesignerPlugin::showDesigner                                                                                                qmldesignerplugin.cpp  318  0x57e360ec 
   13  <lambda_c2a8bd31a47f8c06691639d5b43241c5>::operator()                                                                                       qmldesignerplugin.cpp  282  0x57e3bded 
   14  QtPrivate::FunctorCall<QtPrivate::IndexesList<0,1>,QtPrivate::List<Core::Id,Core::Id>,void,<lambda_c2a8bd31a47f8c06691639d5b43241c5>>::call qobjectdefs_impl.h     130  0x57e3d84d 
   15  QtPrivate::Functor<<lambda_c2a8bd31a47f8c06691639d5b43241c5>,2>::call<QtPrivate::List<Core::Id,Core::Id>,void>                              qobjectdefs_impl.h     242  0x57e378e0 
   16  QtPrivate::QFunctorSlotObject<<lambda_c2a8bd31a47f8c06691639d5b43241c5>,2,QtPrivate::List<Core::Id,Core::Id>,void>::impl                    qobject_impl.h         168  0x57e3e908 
   17  QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e7ada8f 
   18  QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e7a0551 
   19  QAnimationDriver::advance                                                                                                                   Qt5Cored                    0x5e7a0061 
   20  Core::ModeManager::currentModeChanged                                                                                                       moc_modemanager.cpp    188  0x5c9e834b 
   ... <Mehr>                                                                                                                                                                             
   

Creator should not crash. A Creator built on Qt 5.8.0 does not crash in this situation.