Description:
------------
When using a constant of '01' as an array key inside of a class, it converts the key to the integer 1.  Outside of a class, it leaves it as '01'.

Reproduce code:
---------------
class mytest
{
  const classConstant = '01';

  private $classArray = array( mytest::classConstant => 'value' );

  public function __construct()
  {
    print_r($this->classArray);
  }
}

$classtest = new mytest();

define( "normalConstant", '01' );
$normalArray = array( normalConstant => 'value' );
print_r($normalArray);


Expected result:
----------------
Array
(
    [01] => value
)
Array
(
    [01] => value
)


Actual result:
--------------
Array
(
    [1] => value
)
Array
(
    [01] => value
)