fixed error for "${" appear in closure body.

[zcodes]

when a closure like this

<?php
$hello = function ($name = 'world') {
    echo "${name}";
}

it will be unserialize failed.

[GrahamCampbell]

Thanks for the PR. Is there any chance you could add a test for this too please?

[zcodes]

@GrahamCampbell a test case was add in the TokenAnalyzerTest.php

[jeremeamia]

This software is no longer maintained. Consider using opis/closure instead.