anchor.diff:      functionTypeParametersSet = null;
       instantiatorTypeArguments = null;
       locals = null;
  -    constantEvaluator = null;
  +    constantEvaluator.env = null;
       labeledStatements = null;
       switchCases = null;
       tryCatches = null;
  
positive.code: import 'package:kernel/external_name.dart'
      show getExternalName, getNativeExtensionUris;
  import 'package:kernel/library_index.dart' show LibraryIndex;
  import 'package:kernel/target/targets.dart' show ConstantsBackend;
  import 'package:kernel/type_algebra.dart'
      show Substitution, containsTypeVariable;
  import 'package:kernel/type_environment.dart' show TypeEnvironment;
  
negative.code:   Set<TypeParameter> functionTypeParametersSet;
    List<DartType> instantiatorTypeArguments;
    LocalVariables locals;
    Map<LabeledStatement, Label> labeledStatements;
    Map<SwitchCase, Label> switchCases;
    Map<TryCatch, TryBlock> tryCatches;
  