Migrate zend_*_property APIs to accept zend_object* instead of zval*

[nikic]

As pointed out by @derickr, the current state of property APIs in PHP 8 is inconsistent. We've migrated large parts of the object-related API to accept zend_object* instead of zval*. However, the zend_*_property() family of functions still accepts zvals. This leaves us in an odd situation where the read_property() object handler accepts zend_object*, while the zend_read_property function accepts zval*. This is inconsistent and causes friction in places where such APIs interact, because it may be necessary to create dummy zval wrappers.

This patch changes the zend_*_property family of functions to require zend_object* as well, in line with underlying APIs.

[morrisonlevi]

Strongly approve. I know we're getting closer and closer to API/ABI stability cutoffs for PHP 8 (we've released beta 1), but I would much rather make this tiny window of time more difficult and have it fixed.

[sgolemon]

LGTM; This is the sort of API break that belongs in a .0 release, so go ahead and merge when ready for inclusion in 8.0.0

[Jan-E]

At least one extension is affected: microsoft/msphpsql#1154 (comment)