Use map to distinguish type feedback vectors.

src/type-feedback-vector.cc

 // Copyright 2014 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.
 
 #include "src/type-feedback-vector.h"
 
 #include "src/code-stubs.h"
 #include "src/ic/ic-inl.h"
 #include "src/ic/ic-state.h"
 #include "src/objects.h"
@@ skipping 173 matching lines @@
   Factory* factory = isolate->factory();
 
   const int slot_count = metadata->slot_count();
   const int length = slot_count + kReservedIndexCount;
   if (length == kReservedIndexCount) {
     return Handle<TypeFeedbackVector>::cast(
         factory->empty_type_feedback_vector());
   }
 
   Handle<FixedArray> array = factory->NewFixedArray(length, TENURED);
+  array->set_map_no_write_barrier(isolate->heap()->type_feedback_vector_map());
   array->set(kMetadataIndex, *metadata);
   array->set(kInvocationCountIndex, Smi::kZero);
 
   DisallowHeapAllocation no_gc;
 
   // Ensure we can skip the write barrier
   Handle<Object> uninitialized_sentinel = UninitializedSentinel(isolate);
   DCHECK_EQ(isolate->heap()->uninitialized_symbol(), *uninitialized_sentinel);
   for (int i = 0; i < slot_count;) {
     FeedbackVectorSlot slot(i);
@@ skipping 807 matching lines @@
 void StoreDataPropertyInLiteralICNexus::ConfigureMonomorphic(
     Handle<Name> name, Handle<Map> receiver_map) {
   Handle<WeakCell> cell = Map::WeakCellForMap(receiver_map);
 
   SetFeedback(*cell);
   SetFeedbackExtra(*name);
 }
 
 }  // namespace internal
 }  // namespace v8