Description:
------------
call_user_func([$obj,"static_method"]) actually performs non-static call.

Most other internal functions that use callbacks (e.g. array_map) are not affected.

Test script:
---------------
<?php
class Foo {
        static public function bar() {
                var_dump($this);
        }
}
try {
        array_map([new Foo, 'bar'],[1]);
} catch (Throwable $e) {
        echo $e->getMessage() . "\n";
}
try {
        call_user_func([new Foo, 'bar']);
} catch (Throwable $e) {
        echo $e->getMessage() . "\n";
}
?>


Expected result:
----------------
Using $this when not in object context
Using $this when not in object context

Actual result:
--------------
Using $this when not in object context
object(Foo)#3 (0) {
}