Change in type-hint representation

Hi, I propose to introduce a unified type representation (zend_type). Now it's going to be used for typing of arguments and return values. Later we should use it for properties and other things. https://gist.github.com/dstogov/1b25079856afccf0d69f77d499cb0ab1 The main changes are in zend_types.h and zend_compile.h, the rest is just an adoption for new type representation. I don't think we need RFC, because this is just an internal change that doesn't change behavior. I got the idea working on typed properties together with Bob and Joe. https://github.com/php/php-src/compare/master...bwoebi:typed_ref_properties I think it would be better to introduce zend_type and then continue work on typed properties. Any comments? Thanks. Dmitry.