[php-src] Issue #13335: Php8.4 PHP_ROUND_AWAY_FROM_ZERO Usable But Defined Says It Doesn't Exist

Issue: https://github.com/php/php-src/issues/13335 Author: oleibman ### Description The following code: ```php <?php var_dump(PHP_ROUND_AWAY_FROM_ZERO, defined(PHP_ROUND_AWAY_FROM_ZERO)); ``` Resulted in this output: ``` int(8) bool(false) ``` But I expected this output instead: ``` int(8) // value is immaterial but this seems to indicate it *is* defined bool(true) ``` This makes it difficult to test if the constant is defined before using it. ### PHP Version Latest nightly ### Operating System Windows 11, but probably all