Fix for-in for large indexes and indexes on proxies

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 1089 matching lines @@
     } else if (FLAG_track_fields && representation.IsSmi()) {
       return IsSmi();
     } else if (FLAG_track_double_fields && representation.IsDouble()) {
       return IsMutableHeapNumber() || IsNumber();
     } else if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
       return IsHeapObject();
     }
     return true;
   }
 
+  // Checks whether two valid primitive encodings of a property name resolve to
+  // the same logical property. E.g., the smi 1, the string "1" and the double
+  // 1 all refer to the same property, so this helper will return true.
+  inline bool KeyEquals(Object* other);
+
   Handle<HeapType> OptimalType(Isolate* isolate, Representation representation);
 
   inline static Handle<Object> NewStorageFor(Isolate* isolate,
                                              Handle<Object> object,
                                              Representation representation);
 
   inline static Handle<Object> WrapForRead(Isolate* isolate,
                                            Handle<Object> object,
                                            Representation representation);
 
@@ skipping 10005 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_