include files for bsd ioctl system calls

[Guy Harris]

>The structure you require,  'struct sgttyb' is defined under SUNOS in
>/usr/include/sys/ttold.h.

That's only because SunOS (4.x, which is the version to which you're
referring) supports the BSD "ioctl"s for backwards compatibility.  Irix
may not do so, in which case getting the structure won't help you one
bit....  (If it *does* do so, they presumably have it defined in a
standard include file, for source compatibility.)