Description:
------------
When looking up the SimpleXMLElement::__construct or using any class that extends 
SimpleXMLElement (the __construct method is final so we can't extend it), 
Reflection reports that the method has no params available, when in fact, there 
are plenty and the '$data' param is required.

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

$ref = new ReflectionClass('SimpleXMLElement');

$constructor = $ref->getConstructor();

print_r($constructor->getParameters());

Expected result:
----------------
Array
(
    'paramname' => 'type'
)

Actual result:
--------------
Array
(
)