[php-src] Issue #14465: Private classes

Issue: https://github.com/php/php-src/issues/14465 Author: neokofg ### Description # Feature Request Please, i need private classes, for my CLM (Compact Layer Modules) architecture, ### Example for example: i want to make exception, that inside a file with class ```php class InvalidCodeException extends Exception {} class ValidateController { // some code throw new InvalidCodeException('Invalid code', 403, $exception); } ``` So it would be great if this exception will be private like: ```php private class InvalidCodeException extends Exception {} class ValidateController { // some code throw new $this->InvalidCodeException('Invalid code', 403, $exception); //idk something like this } ```