[compiler] Track refs through object expressions and property lookups

Summary:
This addresses the issue of the compiler being overly restrictive about refs escaping into object expressions. Rather than erroring whenever a ref flows into an object, we will now treat the object itself as a ref, and apply the same escape rules to it. Whenever we look up a property from a ref value, we now don't know whether that value is itself a ref or a ref value, so we assume it's both.

The same logic applies to ref-accessing functions--if such a function is stored in an object, we'll propagate that property to the object itself and any properties looked up from it.

ghstack-source-id: 5c6fcb895d4a1658ce9dddec286aad3a57a4c9f1
Pull Request resolved: #30821

Author: mvitousek