Description:
------------
DOMNodeList seems to be returning wrong objects.

Reproduce code:
---------------
<?php
class element extends DOMElement {
}

$doc = new DOMDocument;

$e = new element("e");
$doc->appendChild($e);

$e = new element("e");
$doc->appendChild($e);

$e = new element("e");
$doc->appendChild($e);

$nodeList = $doc->getElementsByTagName("e");
foreach($nodeList as $element) {
    var_dump(get_class($element));
}


Expected result:
----------------
string(7) "element"
string(7) "element"
string(7) "element"

Actual result:
--------------
string(10) "DOMElement"
string(10) "DOMElement"
string(7) "element"