entc/gen: check runtime import before executing privacy rules (#1054)

examples/privacyadmin/ent/user_query.go

@@ -295,6 +295,9 @@ func (uq *UserQuery) prepareQuery(ctx context.Context) error {
 		}
 		uq.sql = prev
 	}
+	if user.Policy == nil {
+		return errors.New("ent: uninitialized user.Policy (forgotten import ent/runtime?)")
+	}
 	if err := user.Policy.EvalQuery(ctx, uq); err != nil {
 		return err
 	}