Quick Controls 1 Popups are misplaced when using QGuiApplication with Qt::AA_EnableHighDpiScaling

When using Qt Quick Controls and using QGuiApplication instance, the popups (i.e. ComboBox) are misplaced if Qt::AA_EnableHighDpiScaling is set.

This is reproducible with gallery example by making 2 changes:

• Change the example to use QGuiApplication instead of QApplication
• Add AA_EnableHighDpiScaling flag

The issue does not reproduce when QApplication is used. Controls 2 does not suffer the same issue even when using QGuiApplication.