anchor.diff:    set flags(int value) {}
   
     bool get isCacheable => true;
  +  bool get shouldBeIncludedIntoIndexTable =>
  +      _useCount >= ObjectTable.indexTableUseCountThreshold && isCacheable;
   
     factory ObjectHandle._empty(ObjectKind kind, int flags) {
       switch (kind) {
  
positive.code:   @override
    ObjectKind get kind => ObjectKind.kScript;
  
    @override
    int get flags => _flags;
  
  
negative.code:     int tableSize = 1; // Reserve invalid entry.
      for (var obj in _objects.reversed) {
        assert(obj._reference == null);
        if (obj.shouldBeIncludedIntoIndexTable) {
          // This object will be included into index table.
          ++tableSize;
        } else {
  