Make our own definitions of the POLL* defiens and the pollfd struct only get

done if the sys/poll.h file is missing, as we have seen machines with poll()
present but without the header file and machines that don't get HAVE_POLL
defined but that do have the sys/poll.h header file...

lib/select.h

@@ -46,7 +46,7 @@
  * Definition of pollfd struct and constants for platforms lacking them.
  */
 
-#ifndef HAVE_POLL
+#ifndef HAVE_SYS_POLL_H
 
 #define POLLIN      0x01
 #define POLLPRI     0x02