Drop unused field from PrototypeInfo

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 0b85008b032e78809e526aa1a007eb6c0b548ddb..fd9e8f49333c6884385c2802606f08d6c1ac534e 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6633,9 +6633,7 @@ class PrototypeInfo : public Struct {
   DECLARE_PRINTER(PrototypeInfo)
   DECLARE_VERIFIER(PrototypeInfo)
 
-  static const int kPrototypeObjectOffset = HeapObject::kHeaderSize;
-  static const int kPrototypeUsersOffset =
-      kPrototypeObjectOffset + kPointerSize;
+  static const int kPrototypeUsersOffset = HeapObject::kHeaderSize;
   static const int kValidityCellOffset = kPrototypeUsersOffset + kPointerSize;
   static const int kSize = kValidityCellOffset + kPointerSize;