update SDL soruce to 2.0.14

Edward Rudd

2021-06-15 dec7875a6e23212021e4d9080330a42832dfe02a

 source/src/thread/SDL_systhread.h

@@ -33,11 +33,11 @@
   on success.
*/
#ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD
extern int SDL_SYS_CreateThread(SDL_Thread * thread, void *args,
extern int SDL_SYS_CreateThread(SDL_Thread * thread,
                                pfnSDL_CurrentBeginThread pfnBeginThread,
                                pfnSDL_CurrentEndThread pfnEndThread);
#else
extern int SDL_SYS_CreateThread(SDL_Thread * thread, void *args);
extern int SDL_SYS_CreateThread(SDL_Thread * thread);
#endif

/* This function does any necessary setup in the child thread */