Needed definition of _XOPEN_SOURCE_EXTENDED so DEC C on VMS will see the declarations of fd_set, select() and so on.
Needed definition of _XOPEN_SOURCE_EXTENDED so DEC C on VMS will see
the declarations of fd_set, select() and so on.

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl