*   Add tf_api_version flag. If --define=tf_api_version=2 flag is passed in,
        then bazel will build TensorFlow API version 2.0. Note that TensorFlow
        2.0 is under active development and has no guarantees at this point.
    *   Add additional compression options to TfRecordWriter.
    *   Performance improvements for regex full match operations.
    *   Replace tf.GraphKeys.VARIABLES with `tf.GraphKeys.GLOBAL_VARIABLES`.

T1, T0, SEL1, RED2 // d1 d0 d1 d0 VPERM ZER, RED2, SEL2, RED1 // 0 d1 d0 0 VSQ RED1, RED2, RED2 // Guaranteed not to underflow VSLDB $8, T1, T0, T0 VSLDB $8, T2, T1, T1 VACCQ T0, RED1, CAR1 VAQ T0, RED1, T0 VACCCQ T1, RED2, CAR1, CAR2 VACQ T1, RED2, CAR1, T1 VAQ T2, CAR2, T2 // Second round VPERM T1, T0, SEL1, RED2 // d1 d0 d1 d0 VPERM ZER, RED2, SEL2, RED1 // 0 d1 d0 0 VSQ RED1, RED2, RED2 // Guaranteed not to underflow VSLDB $8, T1, T0, T0 VSLDB $8, T2, T1, T1 VACCQ T0, RED1, CAR1 VAQ T0, RED1, T0...