add .wolfssl_known_macro_extras;

src/wolfio.c: #include <errno.h> if necessary;

wolfcrypt/src/asn.c: gate WOLFSSL_MSG_EX() uses on defined(DEBUG_WOLFSSL), for pedantic C89 compatibility (no variadic macros);

wolfssl/wolfcrypt/wc_port.h: refine setup for XFENCE().