dart2js: Pass type information to constructor rather than add later.

pkg/compiler/lib/src/js_backend/backend.dart

 // Copyright (c) 2012, 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 js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 1088 matching lines @@
       registry.registerInstantiation(typeImplementation.rawType);
     }
     lookupMapAnalysis.registerConstantKey(constant);
   }
 
   void registerInstantiatedConstantType(DartType type, Registry registry) {
     DartType instantiatedType =
         type.isFunctionType ? coreTypes.functionType : type;
     if (type is InterfaceType) {
       registry.registerInstantiation(instantiatedType);
-      if (!type.treatAsRaw && classNeedsRti(type.element)) {
+      if (classNeedsRtiField(type.element)) {
         registry.registerStaticUse(new StaticUse.staticInvoke(
             // TODO(johnniwinther): Find the right [CallStructure].
             helpers.setRuntimeTypeInfo,
             null));
       }
       if (type.element == typeImplementation) {
         // If we use a type literal in a constant, the compile time
         // constant emitter will generate a call to the createRuntimeType
         // helper so we register a use of that.
         registry.registerStaticUse(new StaticUse.staticInvoke(
@@ skipping 348 matching lines @@
 
       enqueue(helpers.startRootIsolate);
       enqueue(helpers.currentIsolate);
       enqueue(helpers.callInIsolate);
     } else {
       enqueuer.addToWorkList(helpers.startRootIsolate);
     }
   }
 
   bool classNeedsRti(ClassElement cls) {
-    return rti.classesNeedingRti.contains(cls.declaration) ||
-        compiler.enabledRuntimeType;
+    if (compiler.enabledRuntimeType) return true;
+    return rti.classesNeedingRti.contains(cls.declaration);
+  }
+
+  bool classNeedsRtiField(ClassElement cls) {
+    if (cls.rawType.typeArguments.isEmpty) return false;
+    if (compiler.enabledRuntimeType) return true;
+    return rti.classesNeedingRti.contains(cls.declaration);
   }
 
   bool isComplexNoSuchMethod(FunctionElement element) =>
       noSuchMethodRegistry.isComplex(element);
 
   bool isDefaultEqualityImplementation(Element element) {
     assert(element.name == '==');
     ClassElement classElement = element.enclosingClass;
     return classElement == coreClasses.objectClass ||
         classElement == helpers.jsInterceptorClass ||
@@ skipping 1710 matching lines @@
 
   @override
   void onImpactUsed(ImpactUseCase impactUse) {
     if (impactUse == DeferredLoadTask.IMPACT_USE && !supportSerialization) {
       // TODO(johnniwinther): Allow emptying when serialization has been
       // performed.
       resolution.emptyCache();
     }
   }
 }