anchor.diff:  // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
   // for details. All rights reserved. Use of this source code is governed by a
   // BSD-style license that can be found in the LICENSE file.
  -
  -// @dart = 2.10
   
   import '../universe/side_effects.dart' show SideEffects;
   import 'nodes.dart';
   
   class ValueSet {
     int size = 0;
  -  List<HInstruction> table;
  -  ValueSetNode collisions;
  -  ValueSet() : table = List<HInstruction>.filled(8, null);
  +  List<HInstruction?> table = List.filled(8, null);
  +  ValueSetNode? collisions;
  +  ValueSet();
   
     bool get isEmpty => size == 0;
     int get length => size;
  
positive.code:     // Reset the table with a bigger capacity.
      assert(capacity > table.length);
      size = 0;
      table = List<HInstruction>.filled(capacity, null);
      collisions = null;
      // Add the old instructions to the new table.
      copyTo(this, oldTable, oldCollisions);
  
negative.code:   final int hash;
    @override
    int get hashCode => hash;
    ValueSetNode? next;
    ValueSetNode(this.value, this.hash, this.next);
  }
  