message: Make `tf.get_static_value` pass-through non-`Tensor` inputs.
  This change allows consistent usage of `tf.get_static_value` without forcing the
  user to have the following indirection:
  `tf.get_static_value(tf.convert_to_tensor(x))` which itself often defeats the point of using `tf.get_static_value` because of requiring graph side-effects only to not have graph side-effects.
diff: @@ -22,6 +22,7 @@ import six
  from tensorflow.core.framework import tensor_pb2
  from tensorflow.core.framework import tensor_shape_pb2
  +from tensorflow.python import pywrap_tensorflow
  from tensorflow.python.framework import composite_tensor
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import tensor_shape
  @@ -808,6 +809,8 @@ def constant_value(tensor, partial=False): # pylint: disable=invalid-name
  """
  if isinstance(tensor, ops.EagerTensor):
  return tensor.numpy()
  + if not pywrap_tensorflow.IsTensor(tensor):
  + return tensor
  ret = _ConstantValue(tensor, partial)
  if ret is not None:
  # The caller may now depend on the constant value of `tensor`, so we
  