Fix issue with storing 31-bit bitfield as Smi.

src/objects-inl.h

 // Copyright 2012 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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 6134 matching lines @@
 void Code::set_type_feedback_info(Object* value, WriteBarrierMode mode) {
   ASSERT(kind() == FUNCTION);
   set_raw_type_feedback_info(value, mode);
   CONDITIONAL_WRITE_BARRIER(GetHeap(), this, kTypeFeedbackInfoOffset,
                             value, mode);
 }
 
 
 uint32_t Code::stub_key() {
   ASSERT(IsCodeStubOrIC());
-  return Smi::cast(raw_type_feedback_info())->value() - Smi::kMinValue;
+  Smi* smi_key = Smi::cast(raw_type_feedback_info());
+  return static_cast<uint32_t>(smi_key->value());
 }
 
 
 void Code::set_stub_key(uint32_t key) {
   ASSERT(IsCodeStubOrIC());
-  set_raw_type_feedback_info(Smi::FromInt(key + Smi::kMinValue));
+  set_raw_type_feedback_info(Smi::FromInt(key));
 }
 
 
 ACCESSORS(Code, gc_metadata, Object, kGCMetadataOffset)
 INT_ACCESSORS(Code, ic_age, kICAgeOffset)
 
 
 byte* Code::instruction_start()  {
   return FIELD_ADDR(this, kHeaderSize);
 }
@@ skipping 1056 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_