anchor.diff:  // TODO(askesc): We should not need to call the constant evaluator
   // explicitly once constant-update-2018 is shipped.
   import 'package:front_end/src/api_prototype/constant_evaluator.dart'
  -    show ConstantEvaluator, EvaluationEnvironment, ErrorReporter;
  +    show ConstantEvaluator, EvaluationEnvironment;
   import 'package:front_end/src/api_unstable/vm.dart'
       show
           CompilerContext,
  
positive.code:   Set<TypeParameter> functionTypeParametersSet;
    List<DartType> instantiatorTypeArguments;
    LocalVariables locals;
    ConstantEvaluator constantEvaluator;
    Map<LabeledStatement, Label> labeledStatements;
    Map<SwitchCase, Label> switchCases;
    Map<TryCatch, TryBlock> tryCatches;
  
negative.code: import 'package:kernel/external_name.dart'
      show getExternalName, getNativeExtensionUris;
  import 'package:kernel/library_index.dart' show LibraryIndex;
  import 'package:kernel/type_algebra.dart'
      show Substitution, containsTypeVariable;
  import 'package:kernel/type_environment.dart' show TypeEnvironment;
  