Some versions if the VMS C system header files seem to require this.
Fixes #24466 on release older than 3.3.
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/24471)
(cherry picked from commit
54e9e254feefb153b4b94330f9d3f20b6120c106)
#ifdef OPENSSL_SYS_VMS
/* So fd_set and friends get properly defined on OpenVMS */
-# define _XOPEN_SOURCE_EXTENDED
+# define _XOPEN_SOURCE_EXTENDED 1
#endif
#include <stdio.h>