dart2js: Add "onlyForRti" to Classes in model of the new emitter.

pkg/compiler/lib/src/js_emitter/program_builder.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.js_emitter.program_builder;
 
 import 'model.dart';
 import '../common.dart';
 import '../js/js.dart' as js;
 
@@ skipping 246 matching lines @@
       }
     }
 
     ClassElement implementation = element.implementation;
     if (isInstantiated) {
       implementation.forEachMember(visitMember, includeBackendMembers: true);
     }
     String name = namer.getNameOfClass(element);
     String holderName = namer.globalObjectFor(element);
     Holder holder = _registry.registerHolder(holderName);
-    Class result = new Class(name, holder, methods, fields);
+    bool onlyForRti =
+        _task.typeTestEmitter.rtiNeededClasses.contains(element);

[sigurdm, 2014/11/25 15:01:43]

Add a comment on `rtiNeededClasses` that it is the classes "only" needed for
rti. Or rename it to `classesOnleNeededForRti` or similar.

+    Class result = new Class(name, holder, methods, fields,
+                             onlyForRti: onlyForRti);
     _classes[element] = result;
     return result;
   }
 
   Method _buildMethod(FunctionElement element, js.Expression code) {
     String name = namer.getNameOfInstanceMember(element);
     return new Method(name, code);
   }
 
   // The getInterceptor methods directly access the prototype of classes.
@@ skipping 118 matching lines @@
     for (ConstantValue constantValue in constantValues) {
       assert(!_constants.containsKey(constantValue));
       String name = namer.constantName(constantValue);
       String constantObject = namer.globalObjectForConstant(constantValue);
       Holder holder = _registry.registerHolder(constantObject);
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     };
   }
 }