message: Increase DetailsPerStream IntervalSetVec size
  Summary: As in title.
diff: @@ -46,7 +46,7 @@ struct OutstandingPacketMetadata {
  struct StreamDetails {
  template <class T>
  - using IntervalSetVec = SmallVec<T, 2 /* stack size */, uint16_t>;
  + using IntervalSetVec = SmallVec<T, 4 /* stack size */, uint16_t>;
  using StreamIntervals = IntervalSet<uint64_t, 1, IntervalSetVec>;
  StreamIntervals streamIntervals;
  