ES6: Add support for Map/Set forEach

src/contexts.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 173 matching lines @@
   V(OBSERVERS_NOTIFY_CHANGE_INDEX, JSFunction, observers_notify_change) \
   V(OBSERVERS_ENQUEUE_SPLICE_INDEX, JSFunction, observers_enqueue_splice) \
   V(OBSERVERS_BEGIN_SPLICE_INDEX, JSFunction, \
     observers_begin_perform_splice) \
   V(OBSERVERS_END_SPLICE_INDEX, JSFunction, \
     observers_end_perform_splice) \
   V(SLOPPY_GENERATOR_FUNCTION_MAP_INDEX, Map, sloppy_generator_function_map) \
   V(STRICT_GENERATOR_FUNCTION_MAP_INDEX, Map, strict_generator_function_map) \
   V(GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX, Map, \
     generator_object_prototype_map) \
-  V(GENERATOR_RESULT_MAP_INDEX, Map, generator_result_map)
+  V(ITERATOR_RESULT_MAP_INDEX, Map, iterator_result_map) \
+  V(MAP_ITERATOR_MAP_INDEX, Map, map_iterator_map) \
+  V(SET_ITERATOR_MAP_INDEX, Map, set_iterator_map)
 
 // JSFunctions are pairs (context, function code), sometimes also called
 // closures. A Context object is used to represent function contexts and
 // dynamically pushed 'with' contexts (or 'scopes' in ECMA-262 speak).
 //
 // At runtime, the contexts build a stack in parallel to the execution
 // stack, with the top-most context being the current context. All contexts
 // have the following slots:
 //
 // [ closure   ]  This is the current function. It is the same for all
@@ skipping 135 matching lines @@
     DERIVED_GET_TRAP_INDEX,
     DERIVED_SET_TRAP_INDEX,
     PROXY_ENUMERATE_INDEX,
     OBSERVERS_NOTIFY_CHANGE_INDEX,
     OBSERVERS_ENQUEUE_SPLICE_INDEX,
     OBSERVERS_BEGIN_SPLICE_INDEX,
     OBSERVERS_END_SPLICE_INDEX,
     SLOPPY_GENERATOR_FUNCTION_MAP_INDEX,
     STRICT_GENERATOR_FUNCTION_MAP_INDEX,
     GENERATOR_OBJECT_PROTOTYPE_MAP_INDEX,
-    GENERATOR_RESULT_MAP_INDEX,
+    ITERATOR_RESULT_MAP_INDEX,
+    MAP_ITERATOR_MAP_INDEX,
+    SET_ITERATOR_MAP_INDEX,
 
     // Properties from here are treated as weak references by the full GC.
     // Scavenge treats them as strong references.
     OPTIMIZED_FUNCTIONS_LIST,  // Weak.
     OPTIMIZED_CODE_LIST,       // Weak.
     DEOPTIMIZED_CODE_LIST,     // Weak.
     MAP_CACHE_INDEX,           // Weak.
     NEXT_CONTEXT_LINK,         // Weak.
 
     // Total number of slots.
@@ skipping 169 matching lines @@
   static bool IsBootstrappingOrGlobalObject(Isolate* isolate, Object* object);
 #endif
 
   STATIC_CHECK(kHeaderSize == Internals::kContextHeaderSize);
   STATIC_CHECK(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CONTEXTS_H_