cps-ir: Support foreign code.

pkg/compiler/lib/src/js_backend/codegen/js_tree_builder.dart

 // Copyright (c) 2014, 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_tree_ir_builder;
 
 import '../../tree_ir/tree_ir_builder.dart' show Builder;
 import 'glue.dart' show Glue;
 import '../../dart2jslib.dart' show Selector, InternalErrorFunction;
 import '../../elements/elements.dart';
@@ skipping 60 matching lines @@
     return new CreateInstance(
         node.classElement,
         node.arguments.map(getVariableUse).toList(growable: false),
         node.typeInformation.map(getVariableUse).toList(growable: false));
   }
 
   Expression visitCreateInvocationMirror(cps_ir.CreateInvocationMirror node) {
     return new CreateInvocationMirror(node.selector,
         node.arguments.map(getVariableUse).toList(growable: false));
   }
+
+  Statement visitForeignCode(cps_ir.ForeignCode node) {
+    if (node.codeTemplate.isExpression) {
+      Expression foreignCode = new ForeignExpression(
+          node.codeTemplate,
+          node.type,
+          node.arguments.map(getVariableUse).toList(growable: false),
+          node.nativeBehavior,
+          node.dependency);
+      return continueWithExpression(node.continuation, foreignCode);
+    } else {
+      assert(node.continuation == null);
+      return new ForeignStatement(
+          node.codeTemplate,
+          node.type,
+          node.arguments.map(getVariableUse).toList(growable: false),
+          node.nativeBehavior,
+          node.dependency);
+    }
+  }
 }