QmlProfiler: Add some sanity checks to the various models

If we pop an event from the stack, then it should be the same type we
pushed earlier.

Change-Id: If4389cb57fa8996b3772fefca92d27c33dc35c65
Task-number: QTCREATORBUG-17885
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmlprofiler/qmlprofilerstatisticsmodel.cpp

@@ -225,7 +225,8 @@ void QmlProfilerStatisticsModel::loadEvent(const QmlEvent &event, const QmlEvent
         break;
     case RangeEnd: {
         // update stats
-
+        QTC_ASSERT(!stack.isEmpty(), return);
+        QTC_ASSERT(stack.top().typeIndex() == event.typeIndex(), return);
         QmlEventStats *stats = &d->data[event.typeIndex()];
         qint64 duration = event.timestamp() - stack.top().timestamp();
         stats->duration += duration;