Handle retrieval of the interceptor value identified by |name|. |object| is the receiver ('this' object) of the interceptor. If retrieval succeeds, set |retval| to the return value. If the requested value does not exist, don't set either |retval| or |exception|. If retrieval fails, set |exception| to the exception that will be thrown. If the property has an associated accessor, it will be called only if you don't set |retval|. Return true (1) if interceptor retrieval was handled, false (0) otherwise.