Description:
------------
Since PHP 7.1.0-beta3, the ReflectionType::__toString() method returns class names with a leading \. This breaks applications comparing the return value with a class string (for instance, Symfony see https://github.com/symfony/symfony/issues/19677)

This behaviour was introduced by https://github.com/php/php-src/pull/2068

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

function test(PDO $reflection) {}

$reflection = new ReflectionFunction('test');

var_dump(PDO::class === (string) $reflection->getParameters()[0]->getType());
var_dump((string) $reflection->getParameters()[0]->getType());

Expected result:
----------------
bool(true)
string(3) "PDO"

Actual result:
--------------
bool(false)
string(3) "\PDO"