Expose "get_modal_stack_top()" to GDScript

doc/classes/Viewport.xml

@@ -46,6 +46,13 @@
 				Returns the total transform of the viewport.
 			</description>
 		</method>
+		<method name="get_modal_stack_top" qualifiers="const">
+			<return type="Control">
+			</return>
+			<description>
+				Returns the topmost modal in the stack.
+			</description>
+		</method>
 		<method name="get_mouse_position" qualifiers="const">
 			<return type="Vector2">
 			</return>

scene/main/viewport.cpp

@@ -2789,6 +2789,8 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("gui_get_drag_data"), &Viewport::gui_get_drag_data);
 	ClassDB::bind_method(D_METHOD("gui_is_dragging"), &Viewport::gui_is_dragging);
 
+	ClassDB::bind_method(D_METHOD("get_modal_stack_top"), &Viewport::get_modal_stack_top);
+
 	ClassDB::bind_method(D_METHOD("set_disable_input", "disable"), &Viewport::set_disable_input);
 	ClassDB::bind_method(D_METHOD("is_input_disabled"), &Viewport::is_input_disabled);