--- gcc/config/xm-svr4.h	2018/04/24 17:51:38	1.1.1.1
+++ gcc/config/xm-svr4.h	2018/04/24 18:10:21	1.1.1.2
@@ -28,3 +28,7 @@ the Free Software Foundation, 675 Mass A
 #define HAVE_VPRINTF
 
 #define POSIX
+
+/* SVR4 provides no sys_siglist,
+   but does offer the same data under another name.  */
+#define sys_siglist _sys_siglist