"rdata.c", line 164: remark(1174): variable "octdigits" was declared but never
          referenced

This was true; octdigits was used in no lib/dns/**/* files.

"rdata.c", line 1485: remark(1506): implicit conversion from "unsigned long"
          to "int":  rounding, sign extension, or loss of accuracy may result
"rdata.c", line 1493: remark(1506): implicit conversion from "unsigned long"
          to "int":  rounding, sign extension, or loss of accuracy may result
"rdata.c", line 1501: remark(1506): implicit conversion from "unsigned long"
          to "int":  rounding, sign extension, or loss of accuracy may result

These three were all in atob_tobuffer, where the value of stroul was being
assigned to an isc_int32_t, which is typedef'd from int and possibly smaller
than long (definitely on the IRIX machine).  The variables in question were
changed from isc_int32_t to long.