Add SDL_internal macro for internal use

Author: madebr

src/SDL_internal.h

@@ -133,6 +133,25 @@
 #include <float.h>
 #endif
 
+/* SDL_ExitProcess is not declared in any public header, although
+   it is shared between some parts of SDL, because we don't want
+   anything calling it without an extremely good reason. */
+#ifdef __WATCOMC__
+extern void SDL_ExitProcess(int exitcode);
+#pragma aux SDL_ExitProcess aborts;
+#endif
+extern SDL_NORETURN void SDL_ExitProcess(int exitcode);
+
+#ifdef HAVE_LIBC
+#define SDL_abort() abort()
+#else
+
+#define SDL_abort() do {                                        \
+        SDL_TriggerBreakpoint();                                \
+        SDL_ExitProcess(42);                                    \
+    } while (0)
+#endif
+
 // If you run into a warning that O_CLOEXEC is redefined, update the SDL configuration header for your platform to add HAVE_O_CLOEXEC
 #ifndef HAVE_O_CLOEXEC
 #define O_CLOEXEC 0