Description:
------------
Interface method override inherited method and implemented in a trait causes fatal error

Test script:
---------------
interface InterfaceY {
    public function y(): string;
}

trait TraitY {
    public function y(): string {
    }
}

class X {
    public function y() {
    }
}

class Y extends X implements InterfaceY {
    use TraitY;
}


Expected result:
----------------
No fatal error. Method Y in TraitY is well defined

Actual result:
--------------
Fatal error:  Declaration of X::y() must be compatible with Y::y(): string


PS


__No fatal error__ when:


class Y extends X implements InterfaceY {
    use TraitY;
    public function y(): string {
    }
}