Unroll more StringDictionary lookup probes both for positive and negative dictionary lookups.

src/code-stubs.h

 // Copyright 2011 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 47 matching lines @@
   V(RevertToNumber)                      \
   V(ToBoolean)                           \
   V(ToNumber)                            \
   V(CounterOp)                           \
   V(ArgumentsAccess)                     \
   V(RegExpExec)                          \
   V(RegExpConstructResult)               \
   V(NumberToString)                      \
   V(CEntry)                              \
   V(JSEntry)                             \
-  V(DebuggerStatement)
+  V(DebuggerStatement)                   \
+  V(StringDictionaryNegativeLookup)
 
 // List of code stubs only used on ARM platforms.
 #ifdef V8_TARGET_ARCH_ARM
 #define CODE_STUB_LIST_ARM(V)  \
   V(GetProperty)               \
   V(SetProperty)               \
   V(InvokeBuiltin)             \
   V(RegExpCEntry)              \
   V(DirectCEntry)
 #else
@@ skipping 834 matching lines @@
  private:
   MacroAssembler* masm_;
   bool previous_allow_;
 
   DISALLOW_COPY_AND_ASSIGN(AllowStubCallsScope);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_