[ic] Temporary resurrect ICStateField to recover performance regression.

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 5112 matching lines @@
     int offset = constant_pool_offset();
     if (offset < instruction_size()) {
       constant_pool = FIELD_ADDR(this, kHeaderSize + offset);
     }
   }
   return constant_pool;
 }
 
 Code::Flags Code::ComputeFlags(Kind kind, ExtraICState extra_ic_state,
                                CacheHolderFlag holder) {
+  // TODO(ishell): remove ICStateField.
   // Compute the bit mask.
   unsigned int bits = KindField::encode(kind) |
+                      ICStateField::encode(MONOMORPHIC) |
                       ExtraICStateField::encode(extra_ic_state) |
                       CacheHolderField::encode(holder);
   return static_cast<Flags>(bits);
 }
 
 Code::Flags Code::ComputeHandlerFlags(Kind handler_kind,
                                       CacheHolderFlag holder) {
   return ComputeFlags(Code::HANDLER, handler_kind, holder);
 }
 
@@ skipping 2768 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_