anchor.diff:  
     @override
     void visitInterceptor(HInterceptor node) {
  +    _metrics.countHInterceptor.add();
       if (node.isConditionalConstantInterceptor) {
  +      _metrics.countHInterceptorConditionalConstant.add();
         assert(node.inputs.length == 2);
         use(node.receiver);
         js.Expression receiverExpression = pop();
  
positive.code:           codeGenerator.parameters, codeGenerator.body);
      });
    }
  }
  
  class SsaCodeGenerator implements HVisitor, HBlockInformationVisitor {
  
negative.code:       SsaCodeGenerator codeGenerator = SsaCodeGenerator(
            this,
            _options,
            _metrics,
            emitter,
            codegen.rtiSubstitutions,
            codegen.rtiRecipeEncoder,
  