Replace generic KeyedStore stub with megamorphic version

src/builtins.h

Index: src/builtins.h
diff --git a/src/builtins.h b/src/builtins.h
index b776f733aed0ea175eb9135563f25377a081b730..a872c7f4222bec23b3f0e41b33519ce49ef3a8ea 100644
--- a/src/builtins.h
+++ b/src/builtins.h
@@ -95,7 +95,6 @@ enum BuiltinExtraArguments {
   V(KeyedStoreIC_PreMonomorphic, KEYED_STORE_IC, PREMONOMORPHIC,               \
     kNoExtraICState)                                                           \
   V(KeyedStoreIC_Megamorphic, KEYED_STORE_IC, MEGAMORPHIC, kNoExtraICState)    \
-  V(KeyedStoreIC_Generic, KEYED_STORE_IC, GENERIC, kNoExtraICState)            \
                                                                                \
   V(KeyedStoreIC_Initialize_Strict, KEYED_STORE_IC, UNINITIALIZED,             \
     StoreIC::kStrictModeState)                                                 \
@@ -103,8 +102,6 @@ enum BuiltinExtraArguments {
     StoreIC::kStrictModeState)                                                 \
   V(KeyedStoreIC_Megamorphic_Strict, KEYED_STORE_IC, MEGAMORPHIC,              \
     StoreIC::kStrictModeState)                                                 \
-  V(KeyedStoreIC_Generic_Strict, KEYED_STORE_IC, GENERIC,                      \
-    StoreIC::kStrictModeState)                                                 \
   V(KeyedStoreIC_SloppyArguments, KEYED_STORE_IC, MONOMORPHIC,                 \
     kNoExtraICState)                                                           \
                                                                                \