[php-src] Issue #12122: Readonly constructor parameter without visibility is promoted to public class property.

Issue: https://github.com/php/php-src/issues/12122 Author: bartvanraaij ### Description https://3v4l.org/1AmKB#v8.2.10 The following code: ```php <?php class MyClass { public function __construct( readonly string $var, ) {} } $a = new MyClass('foo'); var_dump($a); ``` Resulted in this output: ``` object(MyClass)#1 (1) { ["var"]=> string(3) "foo" } ``` The constructor parameter $var is promoted to a class property, because it has the readonly keyword. The [Constructor Property Promotion RFC](https://wiki.php.net/rfc/constructor_promotion) however states that: >When a method parameter is prefixed with one of the visibility keywords public, protected or >private, it is considered to be “promoted”. So without a visibility keyword I would not expect the parameter to be promoted, and be scoped to the constructor method only. I expect the dump of the class to look like this, as it would without the readonly keyword: ``` object(MyClass)#1 (0) { } ``` The source of this bug can be found here, I believe: https://github.com/php/php-src/blob/3f38105740d160e448881b268ebc44bfed20c7db/Zend/zend_compile.c#L7181 You can see here that the parameter is promoted if it has a ZEND_ACC_PPP_MASK keyword or a ZEND_ACC_READONLY. I think the latter is erroneous, but I'm not a C programmer nor knowledgeable about the PHP source so I could be mistaken. ### PHP Version PHP 8.2.10 ### Operating System _No response_