Add HCreateBox

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 'dart:math' as math;
 import 'dart:collection' show Queue;
 import '../common.dart';
 import '../common/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/tasks.dart' show CompilerTask;
 import '../constants/constant_system.dart';
@@ skipping 2091 matching lines @@
     node.instantiatedTypes?.forEach(_registry.registerInstantiation);
     if (node.callMethod != null) {
       _registry
           ?.registerStaticUse(new StaticUse.implicitInvoke(node.callMethod));
     }
     if (node.localFunction != null) {
       _registry?.registerInstantiatedClosure(node.localFunction);
     }
   }
 
+  visitCreateBox(HCreateBox node) {
+    push(new js.ObjectInitializer(<js.Property>[]));
+  }
+
   js.Expression newLiteralBool(
       bool value, SourceInformation sourceInformation) {
     if (_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 913 matching lines @@
     return _closedWorld.anyStrictSubclassOf(cls, (ClassEntity subclass) {
       return !_rtiSubstitutions.isTrivialSubstitution(subclass, cls);
     });
   }
 
   @override
   void visitRef(HRef node) {
     visit(node.value);
   }
 }