Remove dead code dealing with POSIX_SIGNALS.

* atimer.c (set_alarm): Remove dead code, all USG systems define
POSIX_SIGNALS.
* data.c (arith_error): Likewise.
* keyboard.c (input_available_signal, handle_user_signal)
(interrupt_signal): Likewise.
* process.c (sigchld_handler): Likewise.
(create_process): Remove if 0 code.  Remove HPUX conditional when
!defined (POSIX_SIGNALS), it cannot be true.
* syssignal.h: Remove USG5_4 and USG conditionals when
!POSIX_SIGNALS, they cannot be true.

1 files changed, 0 insertions, 6 deletions

diff --git a/src/atimer.c b/src/atimer.c
index 432e2590dad..556272d7918 100644
--- a/src/atimer.c
+++ b/src/atimer.c
@@ -296,12 +296,6 @@ unwind_stop_other_atimers (dummy)
 static void
 set_alarm ()
 {
-#if defined (USG) && !defined (POSIX_SIGNALS)
-  /* USG systems forget handlers when they are used;
-     must reestablish each time.  */
-  signal (SIGALRM, alarm_signal_handler);
-#endif /* USG */
-
   if (atimers)
     {
       EMACS_TIME now, time;