avoid checking for poll on some systems

darwin and interix are known to have broken poll implementations
so we skip the check on those and thus have them use select
unconditionally

configure.ac

@@ -229,7 +229,20 @@ case $host in
     ;;
 esac
 
-AC_CHECK_FUNCS(poll gettimeofday select strtoll)
+case $host in
+  darwin*|interix*)
+    dnl poll() does not work on these platforms
+    dnl Interix: "does provide poll(), but the implementing developer must
+    dnl have been in a bad mood, because poll() only works on the /proc
+    dnl filesystem here"
+    AC_MSG_NOTICE([poll use is disabled on this platform])
+    ;;
+  *)
+    AC_CHECK_FUNCS(poll)
+    ;;
+esac
+
+AC_CHECK_FUNCS(gettimeofday select strtoll)
 
 dnl Check for select() into ws2_32 for Msys/Mingw
 if test "$ac_cv_func_select" != "yes"; then