Description:
------------
In the current snapshot of PHP6, the values stored in the "internal" $_SERVER and $_ENV super-globals cannot be accessed using literal string keys like $_SERVER['SCRIPT_NAME'].

This is because the array keys in these super-globals are of type "string", while literals in the script implicitly are of type "unicode".

This problem does not occur in $_GET, $_POST and $_REQUEST, because the request parameter names are implicitly in unicode too.

Reproduce code:
---------------
// This will fail and print a notice:
print $_ENV['SHELL'] . "\n";

// This works:
foreach($_ENV as $key => $value)
  if ($key == 'SHELL')
    print $_ENV[$key] . "\n";

// This will work:
foreach ($_ENV as $key => $value)
  $_ENV["$key"] = $value;
print $_ENV['SHELL'] . "\n";

Expected result:
----------------
/bin/bash
/bin/bash
/bin/bash

Actual result:
--------------
Notice: Undefined index: SHELL in - on line 2

/bin/bash
/bin/bash