Description:
------------
proc_open returns immediately when a reference to the returned resource is made.

PHP 7.x shows the expected behaviour.

Test script:
---------------
<?php

$spec = [
	0 => STDIN,
	1 => STDOUT,
	2 => STDERR
];

$pipes = [];

echo 'Starting'.PHP_EOL;

$proc = proc_open('sleep 3 ; echo "Hi"', $spec, $pipes);

if (!is_resource($proc)) exit(1);

$ref = &$proc;

// Should wait but does not wait
proc_close($proc);

echo 'Done'.PHP_EOL;


Expected result:
----------------
Starting
Hi (after 3 seconds)
Done

Actual result:
--------------
Starting
Done
Hi (after 3 seconds)