Map known PHP interfaces to zend_class_entry*

Most pre-defined interfaces are accessible via zend_class_entry*
variables declared in the PHP C API - we can use these to add
an interface at MINIT time (rather than having to wait until RINIT to
look up by name) by having a mapping from PHP interface name to them.

This will also be a little faster than looking up by name.

Closes #2013
4 files changed