updae source to 2.0.9 source

Edward Rudd

2019-04-09 9cd2e9ec8fc0127393dfce9c0359d500c8c238be

 source/src/video/x11/SDL_x11window.h

@@ -104,6 +104,7 @@
extern SDL_bool X11_GetWindowWMInfo(_THIS, SDL_Window * window,
                                    struct SDL_SysWMinfo *info);
extern int X11_SetWindowHitTest(SDL_Window *window, SDL_bool enabled);
extern void X11_AcceptDragAndDrop(SDL_Window * window, SDL_bool accept);

#endif /* SDL_x11window_h_ */