Eliminate special keyed load string stub in favor of uniform handlers.

src/builtins.h

 // Copyright 2011 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_BUILTINS_H_
 #define V8_BUILTINS_H_
 
 namespace v8 {
 namespace internal {
 
@@ skipping 70 matching lines @@
                                                                                \
   V(LoadIC_Miss, BUILTIN, UNINITIALIZED, kNoExtraICState)                      \
   V(KeyedLoadIC_Miss, BUILTIN, UNINITIALIZED, kNoExtraICState)                 \
   V(StoreIC_Miss, BUILTIN, UNINITIALIZED, kNoExtraICState)                     \
   V(KeyedStoreIC_Miss, BUILTIN, UNINITIALIZED, kNoExtraICState)                \
   V(LoadIC_Getter_ForDeopt, LOAD_IC, MONOMORPHIC, kNoExtraICState)             \
   V(KeyedLoadIC_Initialize, KEYED_LOAD_IC, UNINITIALIZED, kNoExtraICState)     \
   V(KeyedLoadIC_PreMonomorphic, KEYED_LOAD_IC, PREMONOMORPHIC,                 \
     kNoExtraICState)                                                           \
   V(KeyedLoadIC_Generic, KEYED_LOAD_IC, GENERIC, kNoExtraICState)              \
-  V(KeyedLoadIC_String, KEYED_LOAD_IC, MEGAMORPHIC, kNoExtraICState)           \
                                                                                \
   V(StoreIC_Setter_ForDeopt, STORE_IC, MONOMORPHIC, StoreIC::kStrictModeState) \
                                                                                \
   V(KeyedStoreIC_Initialize, KEYED_STORE_IC, UNINITIALIZED, kNoExtraICState)   \
   V(KeyedStoreIC_PreMonomorphic, KEYED_STORE_IC, PREMONOMORPHIC,               \
     kNoExtraICState)                                                           \
   V(KeyedStoreIC_Generic, KEYED_STORE_IC, GENERIC, kNoExtraICState)            \
                                                                                \
   V(KeyedStoreIC_Initialize_Strict, KEYED_STORE_IC, UNINITIALIZED,             \
     StoreIC::kStrictModeState)                                                 \
@@ skipping 236 matching lines @@
 
   friend class BuiltinFunctionTable;
   friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(Builtins);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_BUILTINS_H_