Generators Revisited

Hi I've tried to review the generators related changes made in PHP-5.5 and improve them from both consistency and performance points of view. The patch also makes a small performance improvement to PHP-5.5 in general, however, it changes some ZE internals that can be used by some extension (e.g. XDebug). You can find the list of changes in the UPGRADING file. http://pastebin.com/AT0SQhAH Please, review the patch and test it with your custom extensions. I would like to commit it on Friday morning. Objections? I also have some additional proposals: 1) EX(Ts) access optimization. With this patch it must be possible to access temporary variables using "execute_data" as the base pointer. "execute_data.Ts" might be removed at all. In general the same optimization might be done for EX(CVs) as well. 2) May be it makes sense to forbid return/yield usage in "finally" blocks using compile time error. Their behaviour is really unclear. Any thoughts? Thanks. Dmitry.