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

pkg/compiler/lib/src/ssa/codegen.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.
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart';
 import '../constants/values.dart';
@@ skipping 1925 matching lines @@
         backend.emitter.constructorAccess(node.element);
     List<js.Expression> arguments = visitArguments(node.inputs, start: 0);
     push(new js.New(jsClassReference, arguments)
         .withSourceInformation(node.sourceInformation));
     // We also use HCreate to instantiate closure classes that belong to
     // function expressions. We have to register their use here, as otherwise
     // code for them might not be emitted.
     if (node.element.isClosure) {
       registry.registerInstantiatedClass(node.element);
     }
-    if (node.instantiatedTypes == null) {
-      return;
-    }
-    node.instantiatedTypes.forEach((type) {
-      registry.registerInstantiation(type);
-    });
+    node.instantiatedTypes?.forEach(registry.registerInstantiation);
   }
 
   js.Expression newLiteralBool(
       bool value, SourceInformation sourceInformation) {
     if (compiler.options.enableMinification) {
       // Use !0 for true, !1 for false.
       return new js.Prefix("!", new js.LiteralNumber(value ? "0" : "1"))
           .withSourceInformation(sourceInformation);
     } else {
       return new js.LiteralBool(value).withSourceInformation(sourceInformation);
@@ skipping 1027 matching lines @@
     registry.registerStaticUse(new StaticUse.staticInvoke(
         helper, new CallStructure.unnamed(argumentCount)));
     return backend.emitter.staticFunctionAccess(helper);
   }
 
   @override
   void visitRef(HRef node) {
     visit(node.value);
   }
 }