Description:
------------
If attempts to instantiate \class\name and class\name are made, autoload is called twice.

Reproduce code:
---------------
<?php
namespace foo;
function __autoload($class)
{
var_dump($class);
eval('namespace ' . $GLOBALS['ns'] . ';class ' . $GLOBALS['class'] . '{}');
}
spl_autoload_register('foo\__autoload');
$ns = 'test';
$class = 'this';
class_exists('\test\this', true);

$a = new \test\this;
$a = new test\this;