[php-src] Issue #10152: Custom properties of DateTimeImmutable child classes are not serialized

Issue: https://github.com/php/php-src/issues/10152 Author: derrabus ### Description The following code: ```php <?php class MyDateTimeImmutable extends DateTimeImmutable { public function __construct( string $datetime = "now", ?DateTimeZone $timezone = null, public ?bool $myProperty = null, ) { parent::__construct($datetime, $timezone); } } $datetime = new MyDateTimeImmutable('2022-12-22T11:26:00Z', myProperty: true); $serialized = serialize($datetime); $unserialized = unserialize($serialized); var_dump($unserialized->myProperty); ``` Resulted in this output: ``` Fatal error: Uncaught Error: Typed property MyDateTimeImmutable::$myProperty must not be accessed before initialization in /path/to/file.php:17 Stack trace: #0 {main} thrown in /path/to/file.php on line 17 ``` But I expected this output instead: ``` bool(true) ``` The propblem can be observed here: https://3v4l.org/8q4Or Apparently, MyDateTimeImmutable::$myProperty is not included in the serialized string anymore on PHP 8.2.0. On PHP 8.0/8.1, it does appear there and is unserialized properly. ### PHP Version PHP 8.2.0 ### Operating System _No response_