internal to AutoGraph.
    *   Improve shape inference for `tf.function` input arguments to unlock more
        Grappler optimizations in TensorFlow 2.x.
    *   Improve automatic control dependency management of resources by allowing
        resource reads to occur in parallel and synchronizing only on writes.
    *   Fix execution order of multiple stateful calls to `experimental_run_v2`
        in `tf.function`.