Changes for SGI from Matthew J Brown <mjb@doc.ic.ac.uk>.

Changes for SGI from Matthew J Brown <mjb@doc.ic.ac.uk>.
	* m/iris4d.h, m/iris5d.h: Don't use the --cckr CC switch if we're
	using GCC.
	(NEED_SIOCTL): Move this to...
	* s/irix3-3.h (NEED_SIOCTL): ... here; apparently it's not
	necessary in irix4-0.h.
	* s/irix4-0.h: Remove declaration of getpty; apparently Irix 4.0
	already declares this elsewhere.
	(PTY_TTY_NAME_SPRINTF): #undef this before re-#defining it.
	* m/ibmps2-aix.h, m/pfa50.h, s/hpux.h, s/isc2-2.h, s/linux.h,
	s/sco4.h, s/usg5-4.h: Remove HAVE_RENAME; configure guesses that now.

	* m/iris4d.h, m/iris5d.h: Don't use the --cckr CC switch if we're
	using GCC.