message: Fix GetRegionOutputs for tf_device.parallel_execute to check number of operands of terminator of each region instead of number of results of terminator.
  The terminators (tf_device.return) have no results and the number of results of each region is determined by the number of operands instead.
diff: @@ -213,14 +213,14 @@ void ParallelExecuteOp::build(Builder* builder, OperationState& state,
  std::vector<OpResult> ParallelExecuteOp::GetRegionOutputs(
  unsigned region_index) {
  int num_region_results =
  - GetRegionBlockWithIndex(region_index).getTerminator()->getNumResults();
  + GetRegionBlockWithIndex(region_index).getTerminator()->getNumOperands();
  std::vector<OpResult> results;
  results.reserve(num_region_results);
  int return_value_offset = 0;
  for (int region_id = 0; region_id < region_index; ++region_id)
  return_value_offset +=
  - GetRegionBlockWithIndex(region_id).getTerminator()->getNumResults();
  + GetRegionBlockWithIndex(region_id).getTerminator()->getNumOperands();
  for (int i = 0; i < num_region_results; ++i)
  results.emplace_back(getOperation()->getOpResult(return_value_offset + i));
  