[php-src] Issue #21284: php 8.5 ReflectionType->getName no longer returns "self"

Issue: https://github.com/php/php-src/issues/21284
Author: bkdotcom

### Description

The following code:

https://3v4l.org/5ACeW#v8.5.3

```php
<?php

class Bar
{
}

class Foo extends Bar
{
    function getSelf (self $a): self
    {        
    }
    
    function getStatic (): static
    {   
    }
}

$refMethodSelf = new ReflectionMethod('Foo', 'getSelf');
$refMethodStatic = new ReflectionMethod('Foo', 'getStatic');
$refParam = $refMethodSelf->getParameters()[0];

print_r(array(
    'paramType' => $refParam->getType()->getName(),
    'returnTypeSelf' => $refMethodSelf->getReturnType()->getName(),
    'returnTypeStatic' => $refMethodStatic->getReturnType()->getName(),
));
```

Resulted in this output:
```
Array
(
    [paramType] => Foo
    [returnTypeSelf] => Foo
    [returnTypeStatic] => static
)
```

But I expected this output instead:
```
Array
(
    [paramType] => self
    [returnTypeSelf] => self
    [returnTypeStatic] => static
)
```


### PHP Version

```plain
PHP 8.5.3 (cli) (built: Feb 10 2026 18:25:51) (NTS)
Copyright (c) The PHP Group
Built by Shivam Mathur
Zend Engine v4.5.3, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.3, Copyright (c), by Zend Technologies
```

### Operating System

MacOS 15.7.4