anchor.diff:    void forEachMember(
         KernelToElementMap elementMap, void f(MemberEntity member)) {
       _ensureMaps(elementMap);
  -    _memberMap.values.forEach((ir.Member member) {
  +    _members.forEach((ir.Member member) {
         f(elementMap.getMember(member));
       });
  -    for (ir.Member member in _setterMap.values) {
  -      if (member is ir.Procedure) {
  -        f(elementMap.getMember(member));
  -      } else {
  -        // Skip fields; these are also in _memberMap.
  -      }
  -    }
     }
   
     /// Return the [ConstructorEntity] for the constructor [name] in [cls].
  
positive.code:   }
  
    void _ensureMaps(KernelToElementMapBase elementMap) {
      if (_memberMap == null) {
        _memberMap = <String, ir.Member>{};
        _setterMap = <String, ir.Member>{};
        _constructorMap = <String, ir.Member>{};
  
        void addMembers(ir.Class c, {bool includeStatic}) {
          for (ir.Member member in c.members) {
            if (member.name.name.contains('#')) {
              // Skip synthetic .dill members.
              continue;
            }
            if (member is ir.Constructor) {
              if (!includeStatic) continue;
              _constructorMap[member.name.name] = member;
            } else if (member is ir.Procedure &&
                member.kind == ir.ProcedureKind.Factory) {
              if (member.function.body is ir.RedirectingFactoryBody) {
                // Don't include redirecting factories.
                continue;
              }
              if (!includeStatic) continue;
              _constructorMap[member.name.name] = member;
            } else if (member is ir.Procedure) {
              if (!includeStatic && member.isStatic) continue;
              if (member.kind == ir.ProcedureKind.Setter) {
                _setterMap[member.name.name] = member;
              } else {
                _memberMap[member.name.name] = member;
              }
            } else if (member is ir.Field) {
              if (!includeStatic && member.isStatic) continue;
              _memberMap[member.name.name] = member;
              if (member.isMutable) {
                _setterMap[member.name.name] = member;
              }
              _memberMap[member.name.name] = member;
            } else {
              failedAt(
                  NO_LOCATION_SPANNABLE, "Unexpected class member node: $member");
            }
          }
        }
  
        if (cls.mixedInClass != null) {
          addMembers(cls.mixedInClass, includeStatic: false);
        }
        addMembers(cls, includeStatic: true);
  
        if (isUnnamedMixinApplication && _constructorMap.isEmpty) {
          // Ensure that constructors are created for the superclass in case it
          // is also an unnamed mixin application.
          ClassEntity superclass = elementMap.getClass(cls.superclass);
          elementMap.elementEnvironment.lookupConstructor(superclass, '');
  
          // Unnamed mixin applications have no constructors when read from .dill.
          // For each generative constructor in the superclass we make a
          // corresponding forwarding constructor in the subclass.
          //
          // This code is copied from
          // 'package:kernel/transformations/mixin_full_resolution.dart'
          var superclassSubstitution = getSubstitutionMap(cls.supertype);
          var superclassCloner =
              new CloneVisitor(typeSubstitution: superclassSubstitution);
  
          for (var superclassConstructor in cls.superclass.constructors) {
            var forwardingConstructor = _buildForwardingConstructor(
                superclassCloner, superclassConstructor);
            cls.addMember(forwardingConstructor);
            _constructorMap[forwardingConstructor.name.name] =
                forwardingConstructor;
          }
        }
      }
    }
  
    /// Return the [MemberEntity] for the member [name] in [cls]. If [setter] is
  
negative.code:   Map<String, ir.Member> _constructorMap;
    Map<String, ir.Member> _memberMap;
    Map<String, ir.Member> _setterMap;
    List<ir.Member> _members; // in declarartion order.
  
    /// Constructor bodies created for this class.
    List<ConstructorBodyEntity> _constructorBodyList;
  