message: [pdsl_core] Fix some missing updates to len field in storage::HashMap::{insert,remove}
diff: @@ -168,6 +168,7 @@ where
  }
  Some((false, probe_index)) => {
  // We can insert into this slot.
  + self.len.set(self.len() + 1);
  self.entries.set(
  probe_index,
  Entry::Occupied(OccupiedEntry{key, val})
  @@ -311,7 +312,10 @@ where
  );
  match self.entries.remove(probe_index).unwrap() {
  Some(Entry::Removed) | None => None,
  - Some(Entry::Occupied(OccupiedEntry{val, ..})) => Some(val),
  + Some(Entry::Occupied(OccupiedEntry{val, ..})) => {
  + self.len.set(self.len() - 1);
  + Some(val)
  + },
  }
  }
  