message: [XLA:Python] Fix Mac OS build failure.
diff: @@ -441,7 +441,10 @@ void CpuCallback::Call(void* result, void** arg_ptrs) {
  continue;
  }
  py::array array = py::cast<py::array>(std::move(output));
  - absl::Span<int64_t const> dims(array.shape(), array.ndim());
  + static_assert(sizeof(ssize_t) == sizeof(int64_t),
  + "Expected ssize_t to be of equal size to int64_t");
  + absl::Span<int64_t const> dims(
  + reinterpret_cast<const int64_t*>(array.shape()), array.ndim());
  if (dims != results_[i].expected_dims) {
  throw std::runtime_error(absl::StrFormat(
  "Mismatched result shape for %d-th return value from CPU callback; "
  @@ -449,7 +452,8 @@ void CpuCallback::Call(void* result, void** arg_ptrs) {
  i, absl::StrJoin(results_[i].expected_dims, ","),
  absl::StrJoin(dims, ",")));
  }
  - absl::Span<int64_t const> strides(array.strides(), array.ndim());
  + absl::Span<int64_t const> strides(
  + reinterpret_cast<const int64_t*>(array.strides()), array.ndim());
  if (strides == results_[i].expected_strides) {
  std::memcpy(outputs[i], array.data(), results_[i].size_in_bytes);
  } else {
  @@ -497,8 +501,10 @@ StatusOr<std::pair<XlaOp, pybind11::object>> PyClient::EmitPythonCallback(
  }
  std::vector<Shape> custom_call_arg_layouts(operands.size() + 1);
  - custom_call_arg_layouts[0] = ShapeUtil::MakeShapeWithDescendingLayout(
  - primitive_util::NativeToPrimitiveType<std::uintptr_t>(), {});
  + static_assert(sizeof(uintptr_t) == sizeof(uint64_t),
  + "Expected 64-bit pointers");
  + custom_call_arg_layouts[0] =
  + ShapeUtil::MakeShapeWithDescendingLayout(U64, {});
  for (int i = 0; i < operands.size(); ++i) {
  TF_ASSIGN_OR_RETURN(Shape shape, builder.GetShape(operands[i]));
  xla::Shape& layout = custom_call_arg_layouts[i + 1];
  