Re-enabled the O_CLOEXEC definition so config headers can be fixed
diff --git a/src/SDL_internal.h b/src/SDL_internal.h
index 3691282..e6da527 100644
--- a/src/SDL_internal.h
+++ b/src/SDL_internal.h
@@ -51,7 +51,8 @@
#include "SDL_config.h"
-#if !defined(O_CLOEXEC) && !defined(HAVE_O_CLOEXEC)
+/* 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
#endif