Fix for #53727 (is_subclass_of resolution with interfaces)

Hi all, Concerning: https://bugs.php.net/bug.php?id=53727 I had put together a quick patch against PHP_5_3 to fix, for what I and others might consider, an issue with is_subclass_of() returning false in this situation: interface A {} class B implements A {} var_dump(is_subclass_of('B', 'A')); // false, should be true It returns false in situations where a class does not have a parent. If a parent currently exists, the above works fine. For example: interface A {} class B implements A {} class C extends B {} var_dump(is_subclass_of('B', 'A')); // true Attached is a patch against PHP_5_3, I can create a patch against PHP_5_4 if need be. I've added a test file and all the current Zend/tests run as expected. Thanks, Ralph

Attachment: [text/x-patch] fix_is_subclass_of.patch