Support for nullsafe function call syntax

Description

The following code:

<?php
class Foo {
    public function __invoke(): string {
        return 'foo invoked';
    }
}

$f = new Foo();
var_Dump($f());

results in this expected output:

string(11) "foo invoked"

$g = null;
$g();

results in this expected output

Fatal error: Uncaught Error: Value of type null is not callable

$g = null;
$g?->__invoke();

results in this expected output:

string(11) "foo invoked"

As the call to ->__invoke() can be shortened to () I would have expected to be able to use the nullsafe operator here as well and write

$g = null;
$g?();

But this results in in this output:

Parse error: syntax error, unexpected token ")"

I would have expected

string(11) "foo invoked"

Is this on purpose? I could not find any mention of invoke in the RFC. So was this overseen?

See also https://3v4l.org/n09i2

PHP Version

All currently supported PHP-Versions

Operating System

No response

Reproduce el comportamiento informado usando los fragmentos de PHP del issue; después, lee el RFC enlazado sobre el operador nullsafe y la implementación y las pruebas existentes para las llamadas nullsafe. Se considera terminado cuando se haya determinado e implementado el tratamiento previsto de $g?(), conservando los errores documentados para las llamadas ordinarias y coincidiendo con el comportamiento esperado.