Description:
------------
In 7.1.0beta3 ReflectionNamedType was introduced, documentation not updated.
The original ReflectionType is not instantiated anymore.

https://github.com/php/php-src/commit/622d2f41d1cdb597f4fafecaaacf66e238742bd4

I don't think this class change is intentional, this would be an even bigger BC break than the discussed ReflectionType::__toString change discussed on internals: http://externals.io/thread/321

Testscript @ See https://3v4l.org/Pmu6c#v710beta3

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

class B
{
    public function test(): B
    {
        
    }
}

function getB(): B
{
    
}

$rc = new ReflectionMethod('B', 'test');
var_dump((string)$rc->getReturnType(), $rc->getReturnType());

$rc = new ReflectionFunction('getB');
var_dump((string)$rc->getReturnType(), $rc->getReturnType());

Expected result:
----------------
string(1) "B"
object(ReflectionType)#2 (0) {
}
string(1) "B"
object(ReflectionType)#1 (0) {
}

Actual result:
--------------
string(2) "\B"
object(ReflectionNamedType)#2 (0) {
}
string(2) "\B"
object(ReflectionNamedType)#1 (0) {
}