Description:
------------
When calling dynamically a static method, with array('static', 'method'), from the right class context, PHP emits an error 'Class 'static' not found'.

Using call_user_func($method); with the same array, leads to the correct call to the method. 

The same problem applies to 'self' and 'parent'.

https://3v4l.org/VKFaQ
https://3v4l.org/0eacu
https://3v4l.org/HkFmd

Test script:
---------------
<?php

class x {   
  static function a() {
  	  // display the current class
     echo __METHOD__;
  } 

  static function b($method) {
  	  // display the current class with method a above
  	  call_user_func($method);
          // This stops with a Fatal Error
  	  $method();
  } 
}

(new x)->b(array('static', 'a'));
?>

Expected result:
----------------
x::a
x::a

Actual result:
--------------
x::a
Fatal error: Uncaught Error: Class 'static' not found