[php-src] Issue #10100: array_merge produces a 0 key index when there is none.

Issue: https://github.com/php/php-src/issues/10100 Author: kevindees ### Description When running array_merge an index of 0 is created when there is no such index on any array that is merged. The issue is with a very specific payload. I have been able to reproduce it consistently. before and after updating PHP, xDebug, and system reboot. M1 Mac. I have a video of the issue as well, if needed. I can do a Zoom call if needed if someone needs to look into this and see it in action. The following code: ```php <?php array_merge([ 'name' => 'Kevin' ]); ``` Resulted in this output: ``` [ '0' => null, 'name' => 'Kevin' ] ``` But I expected this output instead: ``` [ 'name' => 'Kevin' ] ``` <img width="2560" alt="Screenshot 2022-12-13 at 10 44 04 PM" src="https://user-images.githubusercontent.com/348368/207501016-16eb3127-d142-4601-8684-245a836cd4d3.png"> <img width="2560" alt="Screenshot 2022-12-13 at 10 43 45 PM" src="https://user-images.githubusercontent.com/348368/207501020-4f285245-b4f5-4daf-a5be-37f5a79f72a0.png"> <img width="2560" alt="Screenshot 2022-12-13 at 10 42 47 PM" src="https://user-images.githubusercontent.com/348368/207501021-539c393a-bd5b-4518-bc8b-d2a64694dc21.png"> ### PHP Version PHP 8.1.13 and 8.2.0 ### Operating System Mac M1