Remove incorrect guards around inclusion of <signal.h>

Causes problems with UNIX03/SUSv3
Part 2 of change 21916 - oops!

See:
Message-Id: <3FDD06A5.8010004@sun.com>
Subject: Re: UNIX03 & C99 issue with 5.8.2
Date: Mon, 15 Dec 2003 00:56:05 +0000

p4raw-id: //depot/perl@21917

6 files changed, 2 insertions, 16 deletions

diff --git a/doop.c b/doop.c
index 91c7ae1b63..9ca405736d 100644
--- a/doop.c
+++ b/doop.c
@@ -17,10 +17,8 @@
 #include "perl.h"
 
 #ifndef PERL_MICRO
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX)
 #include <signal.h>
 #endif
-#endif
 
 STATIC I32
 S_do_trans_simple(pTHX_ SV *sv)
diff --git a/mg.c b/mg.c
index 0cd694038a..d98a6d5d77 100644
--- a/mg.c
+++ b/mg.c
@@ -397,10 +397,7 @@ Perl_mg_free(pTHX_ SV *sv)
     return 0;
 }
 
-
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX)
 #include <signal.h>
-#endif
 
 U32
 Perl_magic_regdata_cnt(pTHX_ SV *sv, MAGIC *mg)
diff --git a/mpeix/mpeixish.h b/mpeix/mpeixish.h
index 4e96f0ec4a..49ef4355fe 100644
--- a/mpeix/mpeixish.h
+++ b/mpeix/mpeixish.h
@@ -87,9 +87,7 @@
  */
 /* #define ALTERNATE_SHEBANG "#!" / **/
 
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX)
-# include <signal.h>
-#endif
+#include <signal.h>
 
 #ifndef SIGABRT
 #    define SIGABRT SIGILL
diff --git a/plan9/plan9ish.h b/plan9/plan9ish.h
index 1469e10211..c3ae06790a 100644
--- a/plan9/plan9ish.h
+++ b/plan9/plan9ish.h
@@ -93,9 +93,7 @@
  */
 /* #define ALTERNATE_SHEBANG "#!" / **/
 
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX)
-# include <signal.h>
-#endif
+#include <signal.h>
 
 #ifndef SIGABRT
 #    define SIGABRT SIGILL
diff --git a/unixish.h b/unixish.h
index 65ce7d6f16..23b3cadf12 100644
--- a/unixish.h
+++ b/unixish.h
@@ -103,9 +103,7 @@
  */
 /* #define ALTERNATE_SHEBANG "#!" / **/
 
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX) || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
 # include <signal.h>
-#endif
 
 #ifndef SIGABRT
 #    define SIGABRT SIGILL
diff --git a/util.c b/util.c
index 602bc9bbdb..fffc1c372c 100644
--- a/util.c
+++ b/util.c
@@ -18,10 +18,7 @@
 #include "perl.h"
 
 #ifndef PERL_MICRO
-#if !defined(NSIG) || defined(M_UNIX) || defined(__unix) || defined(M_XENIX)
 #include <signal.h>
-#endif
-
 #ifndef SIG_ERR
 # define SIG_ERR ((Sighandler_t) -1)
 #endif