Description:
------------
When using event_base_loop with the flag EVLOOP_NONBLOCK, the callback doesn't seem to be called.

Reproduce code:
---------------
<?php

$base  = event_base_new();
$event = event_new();

event_set($event, STDIN, EV_READ, "ev_read", array($event, $base));
event_base_set($event, $base);
event_add($event);
event_base_loop($base, EVLOOP_NONBLOCK);

for ($i = 10000000; $i > 0; $i--) {
  // do something here
}

echo "End\n";

function ev_read($fd, $events, $arg = null) {
  $data = trim(fgets($fd));
  echo "read: [" . $data . "]\n";
}
---
$ php example.php
foo


Expected result:
----------------
foo
read: [foo]
End


Actual result:
--------------
foo
End
$ foo
foo: command not found