crashes on unloading QNSView

* thread #1: tid = 0x1a9ae, 0x0000000125efe42c DSO`QT_NAMESPACE::QListData::size(this=0x0000000000000060) const + 12 at qlist.h:105, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x60)
  * frame #0: 0x0000000125efe42c DSO`QT_NAMESPACE::QListData::size(this=0x0000000000000060) const + 12 at qlist.h:105
    frame #1: 0x00000001259e7fbd DSO`QT_NAMESPACE::QList<QT_NAMESPACE::QCocoaWindow*>::indexOf(this=0x0000000000000060, t=0x00007fff5fbff058, from=0) const + 109 at qlist.h:941
    frame #2: 0x00000001259e7a11 DSO`QT_NAMESPACE::QList<QT_NAMESPACE::QCocoaWindow*>::removeAll(this=0x0000000000000060, _t=0x00007fff5fbff058) + 49 at qlist.h:849
    frame #3: 0x00000001259dfae2 DSO`QT_NAMESPACE::QCocoaWindow::~QCocoaWindow(this=0x0000000129d0de90) + 498 at qcocoawindow.mm:438
    frame #4: 0x00000001259dfdb5 DSO`QT_NAMESPACE::QCocoaWindow::~QCocoaWindow(this=0x0000000129d0de90) + 21 at qcocoawindow.mm:407
    frame #5: 0x00000001259dfdd9 DSO`QT_NAMESPACE::QCocoaWindow::~QCocoaWindow(this=0x0000000129d0de90) + 25 at qcocoawindow.mm:407
    frame #6: 0x00000001261323d3 DSO`QT_NAMESPACE::QWindow::destroy(this=0x000000012206bf20) + 499 at qwindow.cpp:1626
    frame #7: 0x0000000126132197 DSO`QT_NAMESPACE::QWindow::~QWindow(this=0x000000012206bf20) + 55 at qwindow.cpp:204
    frame #8: 0x00000001252afb94 DSO`QT_NAMESPACE::QQuickWindow::~QQuickWindow(this=0x000000012206bf20) + 612 at qquickwindow.cpp:1150

----

(lldb) up
frame #3: 0x00000001259dfae2 DSO`QT_NAMESPACE::QCocoaWindow::~QCocoaWindow(this=0x0000000129d0de90) + 498 at qcocoawindow.mm:438
   435
   436 	    // While it is unlikely that this window will be in the popup stack
   437 	    // during deletetion we clear any pointers here to make sure.
-> 438 	    QCocoaIntegration::instance()->popupWindowStack()->removeAll(this);
   439
   440 	    foreach (QCocoaWindow *child, m_childWindows) {
   441 	       [m_nsWindow removeChildWindow:child->m_nsWindow];
(lldb) f 2
frame #2: 0x00000001259e7a11 DSO`QT_NAMESPACE::QList<QT_NAMESPACE::QCocoaWindow*>::removeAll(this=0x0000000000000060, _t=0x00007fff5fbff058) + 49 at qlist.h:849
   846 	template <typename T>
   847 	Q_OUTOFLINE_TEMPLATE int QList<T>::removeAll(const T &_t)
   848 	{
-> 849 	    int index = indexOf(_t);
   850 	    if (index == -1)
   851 	        return 0;
   852