Description:
------------
When calling proc_open inside the body
of a function, pipes generated don't survive
function's lifespan. resource is still there
but stream is closed.

Reproduce code:
---------------
function foobar() {
    $proc = proc_open(
        "/usr/bin/php",
        array(
            0 => array('pipe', 'r'),
            1 => array('pipe', 'w'),
            2 => array('pipe', 'w')
        ),
        $pipes
    );
    var_dump($pipes);
    return $pipes;
}
$should_be_pipes = foobar();
var_dump($should_be_pipes);

Expected result:
----------------
array(3) {
  [0]=>
  resource(6) of type (stream)
  [1]=>
  resource(7) of type (stream)
  [2]=>
  resource(8) of type (stream)
}
array(3) {
  [0]=>
  resource(6) of type (stream)
  [1]=>
  resource(7) of type (stream)
  [2]=>
  resource(8) of type (stream)
}

Actual result:
--------------
array(3) {
  [0]=>
  resource(6) of type (stream)
  [1]=>
  resource(7) of type (stream)
  [2]=>
  resource(8) of type (stream)
}
array(3) {
  [0]=>
  resource(6) of type (Unknown)
  [1]=>
  resource(7) of type (Unknown)
  [2]=>
  resource(8) of type (Unknown)
}