Workaround for get_parent_class in hhvm if spl_autoloader is used

child_file.php

<?php

spl_autoload_register(function ($class) {
   // in hhvm, this will not get executed
    include 'parent_file.php';
});

// this will return false in hhvm due to https://github.com/facebook/hhvm/issues/2097
var_dump(get_parent_class('C'));

// this works in hhvm (should be considered only as a temp workaround)
// see https://github.com/facebook/hhvm/blob/master/hphp/runtime/ext/ext_spl.cpp#L173 for implementation details
var_dump(array_shift(class_parents('C')));

parent_file.php

<?php

class B {}
class C extends B {}