Header file update
The change in TCPIPLibs-5_69 updated sys/time.h from FreeBSD revision 18397, but omitted the changes to the sys/stat.h header file which was in the same commit. Merge those too and bring it up to RCS revision 8.12 from 1995.
Fixes https://www.riscosopen.org/forum/forums/4/topics/16275