Description:
------------
The new ReflectionAttribute class does not implement the Reflector interface. This is not really a big problem, but feels inconsistent and somewhat unintended.

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

$classes = [
    'ReflectionClass',
    'ReflectionClassConstant',
    'ReflectionZendExtension',
    'ReflectionExtension',
    'ReflectionFunction',
    'ReflectionFunctionAbstract',
    'ReflectionMethod',
    'ReflectionNamedType',
    'ReflectionObject',
    'ReflectionParameter',
    'ReflectionProperty',
    'ReflectionType',
    'ReflectionAttribute',
];

foreach ($classes as $class) {
    $isReflector = class_implements($class, 'Reflector') ? 'yes' : 'no';
    $class = str_pad($class, 30);
    echo "$class$isReflector\n";
}

Expected result:
----------------
ReflectionClass               yes
ReflectionClassConstant       yes
ReflectionZendExtension       yes
ReflectionExtension           yes
ReflectionFunction            yes
ReflectionFunctionAbstract    yes
ReflectionMethod              yes
ReflectionNamedType           yes
ReflectionObject              yes
ReflectionParameter           yes
ReflectionProperty            yes
ReflectionType                yes
ReflectionAttribute           yes

Actual result:
--------------
ReflectionClass               yes
ReflectionClassConstant       yes
ReflectionZendExtension       yes
ReflectionExtension           yes
ReflectionFunction            yes
ReflectionFunctionAbstract    yes
ReflectionMethod              yes
ReflectionNamedType           yes
ReflectionObject              yes
ReflectionParameter           yes
ReflectionProperty            yes
ReflectionType                yes
ReflectionAttribute           no