Description:
------------
While in a namespace, setting a class constant to another constant will cause an Undefined Constant error upon instantiation on a cache hit

Reproduce code:
---------------
<?php
namespace NS;
class Foo {
    const BAR = PHP_VERSION;
    public function __construct() {
        echo "Test\n";
    }
}

new NS::Foo();


Expected result:
----------------
$ php-cgi -T 2 test.php
X-Powered-By: PHP/5.3.0-dev
Content-type: text/html

Test
X-Powered-By: PHP/5.3.0-dev
Content-type: text/html

<br />
Test

Elapsed time: 0.001163 sec


Actual result:
--------------
$ php-cgi -T 2 test.php
X-Powered-By: PHP/5.3.0-dev
Content-type: text/html

Test
X-Powered-By: PHP/5.3.0-dev
Content-type: text/html

<br />
<b>Notice</b>:  Use of undefined constant &#65533;&#65533;PHP_VERSION - assumed '&#65533;&#65533;PHP_VERSION' in <b>/home/alex/test.php</b> on line <b>10</b><br />
Test

Elapsed time: 0.001163 sec