update SDL soruce to 2.0.14

Edward Rudd

2021-06-15 dec7875a6e23212021e4d9080330a42832dfe02a

 source/src/events/SDL_events_c.h

@@ -46,6 +46,7 @@
extern int SDL_SendAppEvent(SDL_EventType eventType);
extern int SDL_SendSysWMEvent(SDL_SysWMmsg * message);
extern int SDL_SendKeymapChangedEvent(void);
extern int SDL_SendLocaleChangedEvent(void);

extern int SDL_SendQuit(void);