Remove requiredTypes

pkg/compiler/lib/src/resolution/constructors.dart

 // Copyright (c) 2015, 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.resolution.constructors;
 
 import '../common.dart';
 import '../compiler.dart' show
     Compiler;
 import '../constants/constructors.dart' show
@@ skipping 549 matching lines @@
     return result;
   }
 
   ConstructorResult visitTypeAnnotation(TypeAnnotation node) {
     // This is not really resolving a type-annotation, but the name of the
     // constructor. Therefore we allow deferred types.
     DartType type = resolver.resolveTypeAnnotation(
         node,
         malformedIsError: inConstContext,
         deferredIsMalformed: false);
-    registry.registerRequiredType(type, resolver.enclosingElement);
     return constructorResultForType(node, type);
   }
 
   ConstructorResult visitSend(Send node) {
     ConstructorResult receiver = visit(node.receiver);
     assert(invariant(node.receiver, receiver != null,
         message: 'No result returned for $node.receiver.'));
     if (receiver.kind != null) {
       assert(invariant(node, receiver.element.isErroneous,
           message: "Unexpected prefix result: $receiver."));
@@ skipping 173 matching lines @@
     // constructors.
     return null;
   }
   // TODO(johnniwinther): Use [Name] for lookup.
   ConstructorElement constructor = cls.lookupConstructor(constructorName);
   if (constructor != null) {
     constructor = constructor.declaration;
   }
   return constructor;
 }