Provider for names of methods of the current classes

[stof]

My use case is to provide completion for an API similar to the EventSubscriberInterface of Symfony, but simpler (no priority, and no support for multiple callbacks):

class Foo implements MyCustomSubscriberInterface
{
    public static function getSubscribedProcessors()
    {
        // Array values are named of public methods of the class
        return [
            'test' => 'processTest',
            // ...
        ];
    }
}

It would be great if we could have a provider to register such completion (and the corresponding GoTo btw).