dart2js cps: Fix codegen for foreign statements.

pkg/compiler/lib/src/tree_ir/tree_ir_tracer.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 tree_ir_tracer;
 
 import 'dart:async' show EventSink;
 import '../tracer.dart';
 import 'tree_ir_nodes.dart';
 
@@ skipping 310 matching lines @@
     }
     printStatement(null, '$object.$field = $value');
   }
 
   String expr(Expression e) {
     return e.accept(new SubexpressionVisitor(names));
   }
 
   @override
   visitForeignStatement(ForeignStatement node) {
-    printStatement(null, 'foreign');
+    printStatement(null, 'foreign ${node.codeTemplate.source}');
   }
 }
 
 class SubexpressionVisitor extends ExpressionVisitor<String> {
   Names names;
 
   SubexpressionVisitor(this.names);
 
   String visitVariableUse(VariableUse node) {
     return names.varName(node.variable);
@@ skipping 173 matching lines @@
   }
 
   @override
   String visitInterceptor(Interceptor node) {
     return 'Interceptor(${visitExpression(node.input)})';
   }
 
   @override
   String visitForeignExpression(ForeignExpression node) {
     String arguments = node.arguments.map(visitExpression).join(', ');
-    return 'Foreign "${node.codeTemplate}"($arguments)';
+    return 'Foreign "${node.codeTemplate.source}"($arguments)';
   }
 
   @override
   String visitApplyBuiltinOperator(ApplyBuiltinOperator node) {
     String args = node.arguments.map(visitExpression).join(', ');
     return 'ApplyBuiltinOperator ${node.operator} ($args)';
   }
 }
 
 /**
@@ skipping 14 matching lines @@
       String prefix = v.element == null ? 'v' : '${v.element.name}_';
       while (name == null || _usedNames.contains(name)) {
         name = "$prefix${_counter++}";
       }
       _names[v] = name;
       _usedNames.add(name);
     }
     return name;
   }
 }