Handle for-in loops

test/codegen/expect/server_mode/html_input.html

Index: test/codegen/expect/server_mode/html_input.html
diff --git a/test/codegen/expect/server_mode/html_input.html b/test/codegen/expect/server_mode/html_input.html
index 01523e4ef29ee633c5f407fb1b1024dd76fb7ee7..2794d5e25f20e13df3acb65ee7231df3e026c6df 100644
--- a/test/codegen/expect/server_mode/html_input.html
+++ b/test/codegen/expect/server_mode/html_input.html
@@ -2,7 +2,7 @@
 <script src="cached/c947f9f732203b97dd2882e63da78dbe/dev_compiler/runtime/harmony_feature_check.js"></script>
 <script src="cached/1e28faa1c245886eee30f7f61662b59a/dev_compiler/runtime/dart_runtime.js"></script>
 <script src="cached/5a67eb20221232fcf6763601b852c520/dev_compiler/runtime/dart/core.js"></script>
-<script src="cached/698a3052a4b95f9f1f6e7259c2a6f005/dev_compiler/runtime/dart/collection.js"></script>
+<script src="cached/56a73846f9ab3a092feae34e3ed23461/dev_compiler/runtime/dart/collection.js"></script>
 <script src="cached/2be62665885412f7ff01a6f7b0825ebd/dev_compiler/runtime/dart/math.js"></script>
 <script src="cached/c36af93826f645c97ae65b44badd998b/dev_compiler/runtime/messages_widget.js"></script>
 <link rel="stylesheet" href="cached/307a7ef1e0cd0544d55c6f768f5e3886/dev_compiler/runtime/messages.css">