Description:
------------
When using aliases for tables and/or columns in a MySQL query. The method PDOStatement::getColumnMeta() will not tell you anything about the original table / column name. In the MySQLi extension the information about the original table / column name was represented as 'orgtable' and 'orgname' this would be a very nice addition to the PDO extension.

Reproduce code:
---------------
SQL:
CREATE TABLE `foobar` (
  `bar` varchar(255) default NULL
) ENGINE=MEMORY;

PHP:
print_r(
  $PDO->query("SELECT foo.bar as baz FROM foobar foo")
      ->getColumnMeta(0)
);

Expected result:
----------------
Array
(
    [native_type] => VAR_STRING
    [flags] => Array
        (
        )

    [table] => foo
    [orgtable] => foobar
    [name] => baz
    [orgname] => bar
    [len] => 255
    [precision] => 0
    [pdo_type] => 2
)

Actual result:
--------------
Array
(
    [native_type] => VAR_STRING
    [flags] => Array
        (
        )

    [table] => foo
    [name] => baz
    [len] => 255
    [precision] => 0
    [pdo_type] => 2
)