Replaced all but one use of IRIX5_3 by feature-based macros.

(Thanks to Brian Ostrom <briano@netscape.com>.)
Modified files: IRIX.mk and irix.c.

nsprpub/config/IRIX.mk

@@ -32,13 +32,13 @@ endif
 endif
 
 #
-# On IRIX 5.3, classic nspr (user-level threads on top of sprocs)
+# On IRIX 5.x, classic nspr (user-level threads on top of sprocs)
 # is the default (and only) implementation strategy.
 #
-# On IRIX 6.2 and later, the default implementation strategy is
+# On IRIX 6.x and later, the default implementation strategy is
 # pthreads.  Classic nspr is also available.
 #
-ifeq ($(OS_RELEASE),5.3)
+ifeq ($(basename $(OS_RELEASE)),5)
 CLASSIC_NSPR = 1
 endif
 
@@ -114,6 +114,10 @@ ifeq ($(OS_RELEASE),5.3)
 OS_CFLAGS		+= -DIRIX5_3
 endif
 
+ifneq ($(basename $(OS_RELEASE)),5)
+OS_CFLAGS		+= -D_PR_HAVE_SGI_PRDA_PROCMASK
+endif
+
 ifeq (,$(filter-out 6.5,$(OS_RELEASE)))
 OS_CFLAGS		+= -D_PR_HAVE_GETPROTO_R -D_PR_HAVE_GETPROTO_R_POINTER
 endif

nsprpub/pr/src/md/unix/irix.c

@@ -831,7 +831,7 @@ _MD_CleanupBeforeExit(void)
      }
 }
 
-#ifndef IRIX5_3
+#ifdef _PR_HAVE_SGI_PRDA_PROCMASK
 extern void __sgi_prda_procmask(int);
 #endif
 
@@ -871,7 +871,7 @@ _MD_InitThread(PRThread *thread, PRBool wakeup_parent)
 		thread->md.id = getpid();
         setblockproccnt(thread->md.id, 0);
 		_MD_SET_SPROC_PID(getpid());	
-#ifndef IRIX5_3
+#ifdef _PR_HAVE_SGI_PRDA_PROCMASK
 		/*
 		 * enable user-level processing of sigprocmask(); this is an
 		 * undocumented feature available in Irix 6.2, 6.3, 6.4 and 6.5
@@ -1442,7 +1442,7 @@ void _MD_IrixInit()
     PRThread *me = _PR_MD_CURRENT_THREAD();
 	int rv;
 
-#ifndef IRIX5_3
+#ifdef _PR_HAVE_SGI_PRDA_PROCMASK
 	/*
 	 * enable user-level processing of sigprocmask(); this is an undocumented
 	 * feature available in Irix 6.2, 6.3, 6.4 and 6.5
@@ -1463,7 +1463,7 @@ void _MD_IrixInit()
      * Change the name of the core file from core to core.pid,
      * This is inherited by the sprocs created by this process
      */
-#ifndef IRIX5_3
+#ifdef PR_COREPID
     prctl(PR_COREPID, 0, 1);
 #endif
     /*