Description:
------------
If I used ReflectionParameter for method parametr that include default value with 
array, I couldn't get its defaultValue.

Fatal error is throws:
"PHP Fatal error:  Undefined class constant 'self::CONST_NAME' in /path/file.php 
on line NNN".

See test script.

Tested on php 5.2.13, php 5.3.2.

Test script:
---------------
<?php
class A {
    const B = 'BB';
    const C = 'CC';

    public function some(array $param = array(self::B, self::C))
    {
        var_export($param);
    }
}

$refClass = new ReflectionClass('A');
$refMethods = $refClass->getMethod('some')->getParameters();

$refMethod = array_pop($refMethods);
if ($refMethod->isDefaultValueAvailable()) {
    var_export($refMethod->getDefaultValue()); //Fatal error
}

Expected result:
----------------
array (
  0 => 'BB',
  1 => 'CC',
)

Actual result:
--------------
PHP Fatal error:  Cannot access self:: when no class scope is active in test.php 
on line 15