--- a/src/hotspot/share/oops/klass.hpp	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/hotspot/share/oops/klass.hpp	Thu Oct 17 20:53:35 2019 +0100
@@ -28,6 +28,7 @@
 #include "classfile/classLoaderData.hpp"
 #include "memory/iterator.hpp"
 #include "memory/memRegion.hpp"
+#include "oops/markWord.hpp"
 #include "oops/metadata.hpp"
 #include "oops/oop.hpp"
 #include "oops/oopHandle.hpp"
@@ -159,7 +160,7 @@
   // Biased locking implementation and statistics
   // (the 64-bit chunk goes first, to avoid some fragmentation)
   jlong    _last_biased_lock_bulk_revocation_time;
-  markOop  _prototype_header;   // Used when biased locking is both enabled and disabled for this type
+  markWord _prototype_header;   // Used when biased locking is both enabled and disabled for this type
   jint     _biased_lock_revocation_count;
 
   // vtable length
@@ -468,8 +469,6 @@
   virtual bool should_be_initialized() const    { return false; }
   // initializes the klass
   virtual void initialize(TRAPS);
-  // lookup operation for MethodLookupCache
-  friend class MethodLookupCache;
   virtual Klass* find_field(Symbol* name, Symbol* signature, fieldDescriptor* fd) const;
   virtual Method* uncached_lookup_method(const Symbol* name, const Symbol* signature,
                                          OverpassLookupMode overpass_mode,
@@ -523,9 +522,18 @@
   virtual void remove_java_mirror();
   virtual void restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS);
 
- public:
-  // subclass accessor (here for convenience; undefined for non-klass objects)
-  virtual bool is_leaf_class() const { fatal("not a class"); return false; }
+  bool is_unshareable_info_restored() const {
+    assert(is_shared(), "use this for shared classes only");
+    if (has_raw_archived_mirror()) {
+      // _java_mirror is not a valid OopHandle but rather an encoded reference in the shared heap
+      return false;
+    } else if (_java_mirror.ptr_raw() == NULL) {
+      return false;
+    } else {
+      return true;
+    }
+  }
+
  public:
   // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP
   // These functions describe behavior for the oop not the KLASS.
@@ -619,9 +627,9 @@
 
   // Biased locking support
   // Note: the prototype header is always set up to be at least the
-  // prototype markOop. If biased locking is enabled it may further be
+  // prototype markWord. If biased locking is enabled it may further be
   // biasable and have an epoch.
-  markOop prototype_header() const      { return _prototype_header; }
+  markWord prototype_header() const      { return _prototype_header; }
   // NOTE: once instances of this klass are floating around in the
   // system, this header must only be updated at a safepoint.
   // NOTE 2: currently we only ever set the prototype header to the
@@ -630,7 +638,7 @@
   // wanting to reduce the initial scope of this optimization. There
   // are potential problems in setting the bias pattern for
   // JVM-internal oops.
-  inline void set_prototype_header(markOop header);
+  inline void set_prototype_header(markWord header);
   static ByteSize prototype_header_offset() { return in_ByteSize(offset_of(Klass, _prototype_header)); }
 
   int  biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; }