anchor.diff:    final B b;
     const C(this.b);
   }
  -var v = const C(const A());''');
  +const A u = const A();
  +var v = const C(u);''');
       await computeAnalysisResult(source);
       assertErrors(source, [
         CheckedModeCompileTimeErrorCode.CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH
  
positive.code:   }
  
    test_fieldFormalParameterAssignableToField_typedef() async {
      // foo has the runtime type dynamic -> dynamic, so it should be assignable
      // to A.f.
      Source source = addSource(r'''
  typedef String Int2String(int x);
  
negative.code: 
  @reflectiveTest
  class CheckedModeCompileTimeErrorCodeTest extends ResolverTestCase {
    @override
    AnalysisOptions get defaultAnalysisOptions =>
        new AnalysisOptionsImpl()..strongMode = true;
  
    test_fieldFormalParameterAssignableToField_extends() async {
      // According to checked-mode type checking rules, a value of type B is
      // assignable to a field of type A, because B extends A (and hence is a
  