Introduce two new symbols for vector based ICs.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index a804dc62a6d41dd0fb0abdcf146a16db03981d5f..a08ce227a5e891887cb87298776255b9f394d284 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -8410,6 +8410,12 @@ class TypeFeedbackInfo: public Struct {
   // 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,