Remove support for IRIX

The IRIX port wasn’t really working anyway, and the code was
getting in the way of other changes (e.g., getaddrinfo fixes).
IRIX’s supplier dropped support for IRIX in 2013.
* admin/CPP-DEFINES:
* configure.ac (opsys):
* doc/lispref/os.texi (System Environment):
* etc/MACHINES, etc/PROBLEMS:
* lisp/find-dired.el (find-grep-options):
* lisp/lpr.el (lpr-lp-system):
* lisp/ls-lisp.el (ls-lisp-emulation):
* lisp/mail/rmail.el (rmail-spool-directory):
* lisp/net/net-utils.el (ping-program-options):
* lisp/progmodes/gud.el (gud-irix-p, gud-dbx-use-stopformat-p):
* lisp/progmodes/ps-mode.el (ps-mode-print-function):
* src/conf_post.h [IRIX6_5]:
* src/emacs.c (Vsystem_type):
* src/filelock.c (get_boot_time_1):
* src/process.c (process_send_signal):
* src/unexelf.c (unexec):
Omit IRIX-specific code and/or documentation.
* configure.ac (NON_GCC_TEST_OPTIONS, IRIX6_5, PREFER_VSUSP):
Remove.  All uses removed.
* etc/NEWS: Document the change.

1 files changed, 0 insertions, 3 deletions

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index d57cbcfeb94..3428c2973f0 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -899,9 +899,6 @@ A GNU (glibc-based) system with a FreeBSD kernel.
 @item hpux
 Hewlett-Packard HPUX operating system.
 
-@item irix
-Silicon Graphics Irix system.
-
 @item nacl
 Google Native Client (@acronym{NaCl}) sandboxing system.