Fix for duplicate magic methods calls (bug #63462)

Hi! I made a fix for bug #63462 - https://github.com/php/php-src/pull/258 - which changes a bit how we do guards by unmangling the names before applying guards. This is a slight change of behavior and also means that all private vars with the same name would use the same guard (all protected and public vars with the same name are the same var anyway, so they should be doing it in any case). Since it's a behavior change in core, I'd appreciate a second pair of eyes to see if nothing is broken by it. All tests pass but better safe then sorry. If no problems found in it, I'll commit it soon. Thanks, -- Stanislav Malyshev, Software Architect SugarCRM: http://www.sugarcrm.com/ (408)454-6900 ext. 227