Description:
------------
If you generate a DateTimeZone with new and one with date_create()->getTimeZone, the resulting DateTimeZone objects behave different even if the are of the same time zone.

Reproduce code:
---------------
$tz1 = new DateTimeZone('UTC');
$tz2 = date_create('UTC')->getTimeZone();
echo $tz1->getName(), PHP_EOL;
echo $tz2->getName(), PHP_EOL;
$d = new DateTime('2008-01-01 12:00:00+0200');
$d->setTimeZone($tz1);
echo $d->format(DATE_ISO8601), PHP_EOL;
$d = new DateTime('2008-01-01 12:00:00+0200');
$d->setTimeZone($tz2);
echo $d->format(DATE_ISO8601), PHP_EOL; 

Expected result:
----------------
UTC
UTC
2008-1-1T10:00:00+0000
2008-1-1T10:00:00+0000

Actual result:
--------------
UTC
UTC
2008-01-01T10:00:00+0000
PHP Warning:  DateTime::setTimezone(): Can only do this for zones with ID for now in /Users/tobias/test.php on line 9

Warning: DateTime::setTimezone(): Can only do this for zones with ID for now in /Users/tobias/test.php on line 9
2008-01-01T12:00:00+0200