message: Support XlaGather and XlaScatter ops for bool.
  The undelying XLA ops do work for bool.
diff: @@ -792,7 +792,7 @@ REGISTER_OP("XlaGather")
  .Input("slice_sizes: Tindices")
  .Attr("dimension_numbers: string")
  .Attr("indices_are_sorted: bool")
  - .Attr("T: numbertype")
  + .Attr("T: {numbertype, bool}")
  .Attr("Tindices: {int32, int64}")
  .Output("output: T")
  .SetShapeFn(shape_inference::UnknownShape)
  @@ -813,7 +813,7 @@ REGISTER_OP("XlaScatter")
  .Attr("update_computation: func")
  .Attr("dimension_numbers: string")
  .Attr("indices_are_sorted: bool")
  - .Attr("T: numbertype")
  + .Attr("T: {numbertype, bool}")
  .Attr("Tindices: {int32, int64}")
  .Output("output: T")
  .SetShapeFn(shape_inference::UnchangedShape)
  