Replace PushIfAbsent by a Stack object

src/objects.h

 // Copyright 2015 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/assert-scope.h"
@@ skipping 3467 matching lines @@
   // with the specified attributes.
   // TODO(jkummerow): Deprecated, only used by Object.observe.
   int NumberOfElementsFilterAttributes(PropertyFilter filter);
 
   // Returns the number of enumerable elements in the dictionary.
   // TODO(jkummerow): Deprecated, only used by Object.observe.
   int NumberOfEnumElements() {
     return NumberOfElementsFilterAttributes(ENUMERABLE_STRINGS);
   }
 
-  // Returns true if the dictionary contains any elements that are non-writable,
-  // non-configurable, non-enumerable, or have getters/setters.
-  bool HasComplexElements();
-
   enum SortMode { UNSORTED, SORTED };
 
   // Fill in details for properties into storage.
   // Returns the number of properties added.
   // TODO(jkummerow): Deprecated, only used by Object.observe.
   int CopyKeysTo(FixedArray* storage, int index, PropertyFilter filter,
                  SortMode sort_mode);
   // Collect the keys into the given KeyAccumulator, in ascending chronological
   // order of property creation.
   static void CollectKeysTo(Handle<Dictionary<Derived, Shape, Key> > dictionary,
@@ skipping 212 matching lines @@
       Handle<Object> value, PropertyDetails details, bool used_as_prototype);
 
   // Set an existing entry or add a new one if needed.
   // Return the updated dictionary.
   MUST_USE_RESULT static Handle<SeededNumberDictionary> Set(
       Handle<SeededNumberDictionary> dictionary, uint32_t key,
       Handle<Object> value, PropertyDetails details, bool used_as_prototype);
 
   void UpdateMaxNumberKey(uint32_t key, bool used_as_prototype);
 
+  // Returns true if the dictionary contains any elements that are non-writable,
+  // non-configurable, non-enumerable, or have getters/setters.
+  bool HasComplexElements();
+
   // If slow elements are required we will never go back to fast-case
   // for the elements kept in this dictionary.  We require slow
   // elements if an element has been added at an index larger than
   // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called
   // when defining a getter or setter with a number key.
   inline bool requires_slow_elements();
   inline void set_requires_slow_elements();
 
   // Get the value of the max number key that has been added to this
   // dictionary.  max_number_key can only be called if
@@ skipping 7153 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_