Description:
------------
When I call Bar::aaa(); I expect the self keyword to refer to the Bar class, even if aaa() is defined in a class which Bar extends.

The behavior I observe is that, if aaa() is defined in a class Foo which Bar extends, even when I call Bar::aaa(), self refers to Foo.

In this case the self keyword is not actually that much use, since if I type "self" in the definition of the Foo class, I know the class name and might as well type "Foo".

I had hoped that the self keyword would enable me to override some static functions from a parent class, without forcing me to override the static functions which call them.

Reproduce code:
---------------
<?php

class Foo
{
  public static function aaa()
  {
    return self::bbb();
  }

  public static function bbb()
  {
    return 'Foo';
  }
}

class Bar extends Foo
{
  public static function bbb()
  {
    return 'Bar';
  }
}

var_dump(Bar::aaa());


Expected result:
----------------
string(3) "Bar"


Actual result:
--------------
string(3) "Foo"