Description:
------------
This is a feature request to further improve AST and allow to extend class defined with variable and/or anonymous class. See example.

Instancing anonymous class is already possible.

Test script:
---------------
$cl = get_class(new class () extends \stdClass {
    public function test() {
        echo 'x';
    }
});

var_dump($cl);
$v = new $cl();
$v->test();

$clExtended = get_class(new class () extends $cl /* not possible in PHP 7.4 */ {
    public function test() {
        echo 'y';
    }
});

var_dump($clExtended);
$v = new $clExtended();
$v->test();

Expected result:
----------------
string(101) "class@anonymous�/mnt/www..."
x
string(101) "class@anonymous�/mnt/www..."
y

Actual result:
--------------
not possible in PHP 7.4