*   Update `tf.function`'s `experimental_relax_shapes` to handle composite
        tensors appropriately.
    *   Optimize `tf.function` invocation, by removing redundant list converter.
    *   `tf.function` will retrace when called with a different variable instead
        of simply using the `dtype` & `shape`.
    *   [Improve support](https://github.com/tensorflow/tensorflow/issues/33862)