Rewrite for-in loop as indexing loop for JavaScript indexable arrays

pkg/compiler/lib/src/resolution/registry.dart

Index: pkg/compiler/lib/src/resolution/registry.dart
diff --git a/pkg/compiler/lib/src/resolution/registry.dart b/pkg/compiler/lib/src/resolution/registry.dart
index 8b37559d0bffb36df915917b2bc93cf0e3958d72..8a007cb0a26778bdd93595378dd50ec698ce4f2e 100644
--- a/pkg/compiler/lib/src/resolution/registry.dart
+++ b/pkg/compiler/lib/src/resolution/registry.dart
@@ -331,6 +331,10 @@ class ResolutionRegistry extends Registry {
     backend.resolutionCallbacks.onStackTraceInCatch(this);
   }
 
+  void registerSyncForIn(Node node) {
+    backend.resolutionCallbacks.onSyncForIn(this);
+  }
+
   ClassElement defaultSuperclass(ClassElement element) {
     return backend.defaultSuperclass(element);
   }