tools/nolibc/types: define EXIT_SUCCESS and EXIT_FAILURE

These ones are found in some examples found in man pages and ease
portability tests.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/include/nolibc/types.h

@@ -71,6 +71,9 @@
 #define WEXITSTATUS(status) (((status) & 0xff00) >> 8)
 #define WIFEXITED(status)   (((status) & 0x7f) == 0)
 
+/* standard exit() codes */
+#define EXIT_SUCCESS 0
+#define EXIT_FAILURE 1
 
 /* for select() */
 typedef struct {