message: Only watch tensors with floating dtype in EagerFunc
diff: @@ -104,8 +104,11 @@ class EagerFunc(object):
  """Passes `args` to `self._func`, which is executed eagerly."""
  with context.eager_mode(), backprop.GradientTape() as tape:
  + # Only watch tensors with a floating dtype.
  for tensor in args:
  - tape.watch(tensor)
  + for t in nest.flatten(tensor):
  + if t.dtype.is_floating:
  + tape.watch(t)
  ret = self._func(*args)
  # Use tf.identity to copy the returned tensors to device if neccesary.
  with ops.device(device):
  