How do I inspect the opcode output of use-statements in PHP?

Question

Using

phpdbg -p* tmp.php

on code

<?php
use _ as foo;

outputs

$_main:
  ; (lines=1, args=0, vars=0, tmps=0)
  ; /home/olle/kod/php-src/tmp.php:1-4
L0004 0000 RETURN int(1)

So the use-statement is not part of the opcode? How can I inspect how it's handled by the zend engine (e.g. the parser)?