anchor.diff:      {bool keepFields: false,
       bool strongMode: false,
       bool enableAsserts: false,
  +    bool evaluateAnnotations: true,
       CoreTypes coreTypes,
       ClassHierarchy hierarchy,
       ErrorReporter errorReporter: const _SimpleErrorReporter()}) {
  
positive.code:   }
  
    visitVariableDeclaration(VariableDeclaration node) {
      if (node.isConst) {
        final Constant constant = tryEvaluateWithContext(node, node.initializer);
  
  
negative.code:     CoreTypes coreTypes, TypeEnvironment typeEnvironment,
      {bool keepFields: false,
      bool keepVariables: false,
      bool evaluateAnnotations: true,
      bool strongMode: false,
      bool enableAsserts: false,
      ErrorReporter errorReporter: const _SimpleErrorReporter()}) {
  