--- old/src/hotspot/share/classfile/classLoaderData.cpp	2020-08-05 15:53:48.130153192 -0700
+++ new/src/hotspot/share/classfile/classLoaderData.cpp	2020-08-05 15:53:47.770139640 -0700
@@ -968,3 +968,12 @@
   }
   return false;
 }
+
+InstanceKlass* ClassLoaderData::replace_class(Symbol* class_name, InstanceKlass* k) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  Dictionary* dict = dictionary();
+  unsigned hash  = dict->compute_hash(class_name);
+  int      index = dict->hash_to_index(hash);
+ 
+  return dict->replace_class(index, hash, class_name, k);
+}