R1:fd87a88d710e

Fix static variable usage in Lisk

Summary:
See comment.
This can reveal some pretty bad bugs but HPHP handles this correctly so we already know about them.

Test Plan:
Added `phlog()` to `__call()` and observed what is defined for each method (under PHP). Also:

class C {
function __call($name, $args) {
static $class;
if (!$class) {
$class = get_class($this);
}
return $class;
}
}

class D extends C {
}

class E extends C {
}

$d = new D;
$e = new E…