[ic] Simplify handling of primitive maps.

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 <memory>
 
@@ skipping 1541 matching lines @@
 #else
   void Print() { ShortPrint(); }
   void Print(std::ostream& os) { ShortPrint(os); }  // NOLINT
 #endif
 
  private:
   friend class LookupIterator;
   friend class StringStream;
 
   // Return the map of the root of object's prototype chain.
-  Map* GetRootMap(Isolate* isolate);
+  Map* GetPrototypeChainRootMap(Isolate* isolate);
 
   // Helper for SetProperty and SetSuperProperty.
   // Return value is only meaningful if [found] is set to true on return.
   MUST_USE_RESULT static Maybe<bool> SetPropertyInternal(
       LookupIterator* it, Handle<Object> value, LanguageMode language_mode,
       StoreFromKeyed store_mode, bool* found);
 
   MUST_USE_RESULT static MaybeHandle<Name> ConvertToName(Isolate* isolate,
                                                          Handle<Object> input);
 
@@ skipping 4752 matching lines @@
 
   // [prototype chain validity cell]: Associated with a prototype object,
   // stored in that object's map's PrototypeInfo, indicates that prototype
   // chains through this object are currently valid. The cell will be
   // invalidated and replaced when the prototype chain changes.
   static Handle<Cell> GetOrCreatePrototypeChainValidityCell(Handle<Map> map,
                                                             Isolate* isolate);
   static const int kPrototypeChainValid = 0;
   static const int kPrototypeChainInvalid = 1;
 
+  // Return the map of the root of object's prototype chain.
+  Map* GetPrototypeChainRootMap(Isolate* isolate);
+
   // Returns a WeakCell object containing given prototype. The cell is cached
   // in PrototypeInfo which is created lazily.
   static Handle<WeakCell> GetOrCreatePrototypeWeakCell(
       Handle<JSObject> prototype, Isolate* isolate);
 
   Map* FindRootMap();
   Map* FindFieldOwner(int descriptor);
 
   inline int GetInObjectPropertyOffset(int index);
 
@@ skipping 5415 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_