Call QAccessible::updateAccessibility when a widget is deleted

Merge-request: 1310
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>
(cherry picked from commit df3f763920b1450733817596148e087d11c0c543)

Change-Id: I74fb08104c5dc527f9e9ac88776e4aa2623a3385
Reviewed-on: http://codereview.qt.nokia.com/3041
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>

src/gui/kernel/qwidget.cpp

@@ -1680,6 +1680,10 @@ QWidget::~QWidget()
     if (!d->children.isEmpty())
         d->deleteChildren();
 
+#ifndef QT_NOACCESSIBILITY
+    QAccessible::updateAccessibility(this, 0, QAccessible::ObjectDestroyed);
+#endif
+
     QApplication::removePostedEvents(this);
 
     QT_TRY {