glib/menu.go
func (v *Menu) PrependItem(item *MenuItem) {
	C.g_menu_prepend_item(v.native(), item.native())
}
func (v *Menu) PrependItem(item *MenuItem) {
	C.g_menu_prepend_item(v.native(), item.native())
}
// PrependItem is a wrapper around g_menu_prepend_item().