remove warning prototype SDL_ExitProcess()
diff --git a/src/SDL.c b/src/SDL.c
index 7515a30..2596d55 100644
--- a/src/SDL.c
+++ b/src/SDL.c
@@ -56,6 +56,7 @@ extern int SDL_HelperWindowDestroy(void);
/* This is not declared in any header, although it is shared between some
parts of SDL, because we don't want anything calling it without an
extremely good reason. */
+extern SDL_NORETURN void SDL_ExitProcess(const int exitcode);
SDL_NORETURN void SDL_ExitProcess(const int exitcode)
{
#ifdef __WIN32__