When _XOPEN_SOURCE is defined, make sure it's defined to 500. Required in

http://www.opengroup.org/onlinepubs/007908799/xsh/compilation.html.

Notified by David Wolfe <dwolfe5272@yahoo.com>

crypto/rand/randfile.c

@@ -57,7 +57,7 @@
  */
 
 /* We need to define this to get macros like S_IFBLK and S_IFCHR */
-#define _XOPEN_SOURCE 1
+#define _XOPEN_SOURCE 500
 
 #include <errno.h>
 #include <stdio.h>