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

pkg/compiler/lib/src/compiler.dart

 // Copyright (c) 2012, 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.
 
 part of dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 546 matching lines @@
   /// program uses a type literal.
   void onTypeLiteral(DartType type, Registry registry) {}
 
   /// Called during resolution to notify to the backend that the
   /// program has a catch statement with a stack trace.
   void onStackTraceInCatch(Registry registry) {}
 
   /// Register an is check to the backend.
   void onIsCheck(DartType type, Registry registry) {}
 
+  /// Called during resolution to notify to the backend that the
+  /// program has a for-in loop.
+  void onSyncForIn(Registry registry) {}
+
   /// Register an as check to the backend.
   void onAsCheck(DartType type, Registry registry) {}
 
   /// Registers that a type variable bounds check might occur at runtime.
   void onTypeVariableBoundCheck(Registry registry) {}
 
   /// Register that the application may throw a [NoSuchMethodError].
   void onThrowNoSuchMethod(Registry registry) {}
 
   /// Register that the application may throw a [RuntimeError].
@@ skipping 1844 matching lines @@
     return futureClass.computeType(compiler).createInstantiation([elementType]);
   }
 
   @override
   InterfaceType streamType([DartType elementType = const DynamicType()]) {
     return streamClass.computeType(compiler).createInstantiation([elementType]);
   }
 }
 
 typedef void InternalErrorFunction(Spannable location, String message);