Add extra flag for load-ic stubs in code cache.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index bd3a2844e1012a88055a01d4129f67032923014b..6ceeb9549584a2ecc5c52fe71f319a094dad55ce 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4352,6 +4352,11 @@ class Code: public HeapObject {
     NONEXISTENT
   };
 
+  enum StubHolder {
+    OWN_STUB,
+    PROTOTYPE_STUB
+  };
+
   enum {
     NUMBER_OF_KINDS = LAST_IC_KIND + 1
   };
@@ -4547,6 +4552,8 @@ class Code: public HeapObject {
   class ExtraICStateKeyedAccessStoreMode:
       public BitField<KeyedAccessStoreMode, 1, 4> {};  // NOLINT
 
+  class ExtraICStateStubHolder: public BitField<StubHolder, 0, 1> {};
+
   static inline StrictModeFlag GetStrictMode(ExtraICState extra_ic_state) {
     return ExtraICStateStrictMode::decode(extra_ic_state);
   }
@@ -4563,6 +4570,10 @@ class Code: public HeapObject {
         ExtraICStateStrictMode::encode(strict_mode);
   }
 
+  static inline ExtraICState ComputeExtraICState(StubHolder stub_holder) {
+    return ExtraICStateStubHolder::encode(stub_holder);
+  }
+
   // Flags operations.
   static inline Flags ComputeFlags(
       Kind kind,