[php-src] Issue #9905: constant() behaves unpredictably when class attached to constant is undefined

Issue: https://github.com/php/php-src/issues/9905 Author: AMRoche ### Description The following code: ```php <?php try { \constant("\ExistantClass::non_existant_constant"); } catch (\Throwable|\Error|\Exception $e) { echo($e->getMessage()); } ``` Resulted in this output: ``` ⇒ php test.php PHP Fatal error: Class "ExistantClass" not found in /Users/alexroche/Desktop/test.php on line 4 Fatal error: Class "ExistantClass" not found in /Users/alexroche/Desktop/test.php on line 4 ``` But I expected this output instead: ``` "Error : Class "ExistantClass" not found" ``` (i.e. the error to be caught and the message to be echo'd - what that message is is purely semantics) ### PHP Version 8.0.25, 8.1.12 ### Operating System _No response_