dart2js cps: Fix codegen for foreign statements.

pkg/compiler/lib/src/js_backend/codegen/codegen.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 code_generator;
 
 import 'glue.dart';
 
 import '../../tree_ir/tree_ir_nodes.dart' as tree_ir;
 import '../../tree_ir/tree_ir_nodes.dart' show BuiltinOperator;
@@ skipping 683 matching lines @@
     registry.registerStaticUse(node.dependency);
     return node.codeTemplate.instantiate(visitExpressionList(node.arguments));
   }
 
   @override
   js.Expression visitForeignExpression(tree_ir.ForeignExpression node) {
     return handleForeignCode(node);
   }
 
   @override
-  visitForeignStatement(tree_ir.ForeignStatement node) {
-    return handleForeignCode(node);
+  void visitForeignStatement(tree_ir.ForeignStatement node) {
+    accumulator.add(handleForeignCode(node));
   }
 
   @override
   js.Expression visitApplyBuiltinOperator(tree_ir.ApplyBuiltinOperator node) {
     List<js.Expression> args = visitExpressionList(node.arguments);
     switch (node.operator) {
       case BuiltinOperator.NumAdd:
         return new js.Binary('+', args[0], args[1]);
       case BuiltinOperator.NumSubtract:
         return new js.Binary('-', args[0], args[1]);
@@ skipping 39 matching lines @@
         return js.js("typeof # === 'number' && Math.floor(#) === #", args);
     }
   }
 
   visitFunctionExpression(tree_ir.FunctionExpression node) {
     // FunctionExpressions are currently unused.
     // We might need them if we want to emit raw JS nested functions.
     throw 'FunctionExpressions should not be used';
   }
 }