Add a premonomorphic state to the call target cache.

src/objects.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 8162 matching lines @@
 
   static const int kStorage1Offset = HeapObject::kHeaderSize;
   static const int kStorage2Offset = kStorage1Offset + kPointerSize;
   static const int kFeedbackVectorOffset =
       kStorage2Offset + kPointerSize;
   static const int kSize = kFeedbackVectorOffset + kPointerSize;
 
   // The object that indicates an uninitialized cache.
   static inline Handle<Object> UninitializedSentinel(Isolate* isolate);
 
+  // The object that indicates a cache in pre-monomorphic state.
+  static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate);
+
   // The object that indicates a megamorphic state.
   static inline Handle<Object> MegamorphicSentinel(Isolate* isolate);
 
   // The object that indicates a monomorphic state of Array with
   // ElementsKind
   static inline Handle<Object> MonomorphicArraySentinel(Isolate* isolate,
       ElementsKind elements_kind);
 
   // A raw version of the uninitialized sentinel that's safe to read during
   // garbage collection (e.g., for patching the cache).
@@ skipping 2564 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_