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, 1 insertions, 1 deletions

diff --git a/src/process.c b/src/process.c
index 4359f681b45..69f5e1ddca6 100644
--- a/src/process.c
+++ b/src/process.c
@@ -6464,7 +6464,7 @@ process_send_signal (Lisp_Object process, int signo, Lisp_Object current_group,
           break;
 
         case SIGTSTP:
-#if defined (VSWTCH) && !defined (PREFER_VSUSP)
+#ifdef VSWTCH
           sig_char = &t.c_cc[VSWTCH];
 #else
           sig_char = &t.c_cc[VSUSP];