5218 posix definition of NULL
correct unistd.h and iso/stddef_iso.h
update gate source affected

*** 354,364 ****
                  endseen = numbase64chars = 0;
                  optr = outbuf;
                  while ((fgets(inbuf, sizeof (inbuf), in)) != NULL) {
                          /* process an input line */
                          iptr = inbuf;
!                         while ((curchr = *(iptr++)) != NULL) {
                                  /* decode chars */
                                  if (curchr == '=') /* if end */
                                          endseen++;
  
                                  if (validbase64(curchr))
--- 354,364 ----
                  endseen = numbase64chars = 0;
                  optr = outbuf;
                  while ((fgets(inbuf, sizeof (inbuf), in)) != NULL) {
                          /* process an input line */
                          iptr = inbuf;
!                         while ((curchr = *(iptr++)) != '\0') {
                                  /* decode chars */
                                  if (curchr == '=') /* if end */
                                          endseen++;
  
                                  if (validbase64(curchr))