cps-ir: Support foreign code.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.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 dart2js.ir_nodes_sexpr;
 
 import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
@@ skipping 326 matching lines @@
     String selector = node.selector.name;
     String args = node.arguments.map(access).join(' ');
     return '(CreateInvocationMirror $selector ($args))';
   }
 
   String visitApplyBuiltinOperator(ApplyBuiltinOperator node) {
     String operator = node.operator.toString();
     String args = node.arguments.map(access).join(' ');
     return '(ApplyBuiltinOperator $operator ($args))';
   }
+
+  @override
+  String visitForeignCode(ForeignCode node) {
+    String arguments = node.arguments.map(access).join(' ');
+    String continuation = node.continuation == null ? ''
+        : ' ${access(node.continuation)}';
+    return '(JS ${node.type} ${node.codeTemplate} ($arguments)$continuation)';
+  }
 }
 
 class ConstantStringifier extends ConstantValueVisitor<String, Null> {
   // Some of these methods are unimplemented because we haven't had a need
   // to print such constants.  When printing is implemented, the corresponding
   // parsing support should be added to SExpressionUnstringifier.parseConstant
   // in the dart2js tests (currently in the file
   // tests/compiler/dart2js/backend_dart/sexpr_unstringifier.dart).
 
   String _failWith(ConstantValue constant) {
@@ skipping 94 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     if (!_names.containsKey(node)) return 'MISSING_NAME';
     return _names[node];
   }
 }