use the 'aborts' pragma of Watcom for SDL_NORETURN functions

SDL_ExitProcess(), SDL_AbortAssertion() and SDLTest_BailOut().

(Commit 303c1e0fb0cf for bug #4100 removed SDL_NORETURN from
SDL_ExitProcess() and SDL_AbortAssertion() in order to avoid
warnings from windows builds, but that's temporary I guess..)

src/SDL_assert.c

@@ -120,6 +120,9 @@ static void SDL_GenerateAssertionReport(void)
 }
 
 
+#if defined(__WATCOMC__)
+#pragma aux SDL_ExitProcess aborts;
+#endif
 static void SDL_ExitProcess(int exitcode)
 {
 #ifdef __WIN32__
@@ -138,6 +141,9 @@ static void SDL_ExitProcess(int exitcode)
 }
 
 
+#if defined(__WATCOMC__)
+#pragma aux SDL_AbortAssertion aborts;
+#endif
 static void SDL_AbortAssertion(void)
 {
     SDL_Quit();

src/test/SDL_test_harness.c

@@ -206,6 +206,9 @@ SDLTest_SetTestTimeout(int timeout, void (*callback)())
 /**
 * \brief Timeout handler. Aborts test run and exits harness process.
 */
+#if defined(__WATCOMC__)
+#pragma aux SDLTest_BailOut aborts;
+#endif
 static SDL_NORETURN void
 SDLTest_BailOut()
 {