Move state sentinels into TypeFeedbackVector.

src/type-feedback-vector.h

Index: src/type-feedback-vector.h
diff --git a/src/type-feedback-vector.h b/src/type-feedback-vector.h
index 883a9c176aa3c7142710498834b280d42b8bc758..b6fadba73ea0623ea62ee852f15eda9af3394207 100644
--- a/src/type-feedback-vector.h
+++ b/src/type-feedback-vector.h
@@ -25,6 +25,27 @@ class TypeFeedbackVector : public FixedArray {
   static Handle<TypeFeedbackVector> Copy(Isolate* isolate,
                                          Handle<TypeFeedbackVector> vector);
 
+  // The object that indicates an uninitialized cache.
+  static inline Handle<Object> UninitializedSentinel(Isolate* isolate);
+
+  // The object that indicates a megamorphic state.
+  static inline Handle<Object> MegamorphicSentinel(Isolate* isolate);
+
+  // The object that indicates a premonomorphic state.
+  static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate);
+
+  // The object that indicates a generic state.
+  static inline Handle<Object> GenericSentinel(Isolate* isolate);
+
+  // The object that indicates a monomorphic state of Array with
+  // ElementsKind
+  static inline Handle<Object> MonomorphicArraySentinel(
+      Isolate* isolate, ElementsKind elements_kind);
+
+  // A raw version of the uninitialized sentinel that's safe to read during
+  // garbage collection (e.g., for patching the cache).
+  static inline Object* RawUninitializedSentinel(Heap* heap);
+
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(TypeFeedbackVector);
 };