New function end_of_output_subpipe() added to allow support

for non-posix systems. This is a no-op function for posix systems.

lib/subpipe.c

@@ -166,3 +166,8 @@ reap_subpipe (pid_t pid, char const *program)
     }
 #endif
 }
+
+void
+end_of_output_subpipe (pid_t pid, int fd[2])
+{
+}