// return the first element. Otherwise, `mhlo.get_tuple_element` users are
// simply updated with `replacement`, and all other users are updated with a
// slice of `replacement`.
void ReplaceWithTupleResult(OpBuilder& builder, ValueRange values,
                            ValueRange replacements, bool flatten_tuple) {
  if (flatten_tuple) {
    for (size_t result_index = 0; result_index < values.size(); result_index++)