Add HCreateBox

pkg/compiler/lib/src/ssa/locals_handler.dart

 // Copyright (c) 2016, 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 '../closure.dart';
 import '../common.dart';
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../io/source_information.dart';
@@ skipping 108 matching lines @@
 
   /// Redirects accesses from element [from] to element [to]. The [to] element
   /// must be a boxed variable or a variable that is stored in a closure-field.
   void redirectElement(Local from, CapturedVariable to) {
     assert(redirectionMapping[from] == null);
     redirectionMapping[from] = to;
     assert(isStoredInClosureField(from) || isBoxed(from));
   }
 
   HInstruction createBox() {
-    // TODO(floitsch): Clean up this hack. Should we create a box-object by
-    // just creating an empty object literal?
-    HInstruction box = new HForeignCode(
-        js.js.parseForeignJS('{}'), commonMasks.nonNullType, <HInstruction>[],
-        nativeBehavior: native.NativeBehavior.PURE_ALLOCATION);
+    HInstruction box = new HCreateBox(commonMasks.nonNullType);
     builder.add(box);
     return box;
   }
 
   /// If the scope (function or loop) [node] has captured variables then this
   /// method creates a box and sets up the redirections.
   void enterScope(ast.Node node, Element element) {
     // See if any variable in the top-scope of the function is captured. If yes
     // we need to create a box-object.
     ClosureScope scopeData = closureData.capturingScopes[node];
@@ skipping 534 matching lines @@
   final int hashCode = _nextHashCode = (_nextHashCode + 1).toUnsigned(30);
   static int _nextHashCode = 0;
 
   SyntheticLocal(this.name, this.executableContext);
 
   @override
   MemberElement get memberContext => executableContext.memberContext;
 
   toString() => 'SyntheticLocal($name)';
 }