message: Fix compile for some -c dbg configurations
  We don't have a consistent debug string for std::unique_ptr. We could add one, although for now this just avoids using one in a DCHECK.
diff: @@ -323,7 +323,7 @@ void ImmutableExecutorState::InitializePending(const Graph* graph,
  const ControlFlowInfo& cf_info) {
  for (auto& it : cf_info.unique_frame_names) {
  FrameInfo* finfo = EnsureFrameInfo(it);
  - DCHECK_EQ(finfo->pending_counts, nullptr);
  + DCHECK_EQ(finfo->pending_counts.get(), nullptr);
  finfo->pending_counts =
  absl::make_unique<PendingCounts>(finfo->pending_counts_layout);
  }
  