irix5.2 problem with sys_errlist

[Dave Love <d.love@dl.ac.uk>]

I needed this change to compile syscalls1.c for irix5.2.  Maybe it
should be generalised with a configure test.

===================================================================
RCS file: syscalls1.c,v
retrieving revision 1.1
diff -u -r1.1 syscalls1.c
--- 1.1 1995/01/05 21:25:18
+++ syscalls1.c 1995/01/05 21:27:04
@@ -457,7 +457,10 @@
 const char *errno_msg(int i)
 {
   extern int sys_nerr;
-  const extern char *sys_errlist[]; 
+#ifndef _SGI_SOURCE            /* else problem on Irix5.2, at least */
+  const 
+#endif
+    extern char *sys_errlist[]; 
   return ( i < 0 || i > sys_nerr )
     ? (char*) NULL                     /* i.e., #f */
       : sys_errlist[i];