QVariant properties of value types are not accessible from QML

If I expose a value type to QML using Q_GADGET, QVariant properties of the new type are not accessible from QML. Properties of other types work fine, and QVariant properties of QObject types work correctly.

I've attached a test case that demonstrates this.

This appears to be because QQmlValueTypeWrapper::get wraps the QVariant property value in a QVariant before passing it to QV4::ExecutionEngine::fromVariant, which doesn't handle this case. Indeed, the value of the property appears to be converted to a QV4::VariantObject in the engine.