port sync dwm code

Yuhang Zhao

2023-12-07 e1cbc7a1f19a97c7c00ba32df17b30d4cf32c630

 examples/shared/widgetframe/windowbar_p.h

@@ -43,6 +43,9 @@
        inline void insertDefaultSpace(int index) {
            layout->insertSpacerItem(index, new QSpacerItem(0, 0));
        }

    private:
        Q_DISABLE_COPY_MOVE(WindowBarPrivate)
    };

}