--- old/src/hotspot/share/oops/klass.inline.hpp	2018-05-21 11:52:09.248012489 +0200
+++ new/src/hotspot/share/oops/klass.inline.hpp	2018-05-21 11:52:08.932006859 +0200
@@ -30,8 +30,8 @@
 #include "oops/markOop.hpp"
 
 inline void Klass::set_prototype_header(markOop header) {
-  assert(!header->has_bias_pattern() || is_instance_klass(), "biased locking currently only supported for Java instances");
-  _prototype_header = header;
+  assert(!is_value() || header->is_always_locked(), "Unexpected prototype");
+    _prototype_header = header;
 }
 
 inline bool Klass::is_null(Klass* obj)  { return obj == NULL; }
@@ -71,6 +71,14 @@
   return is_null(v) ? (Klass*)NULL : decode_klass_not_null(v);
 }
 
+inline bool Klass::decode_ptr_is_value_type(narrowKlass v) {
+ return (v & Universe::oop_metadata_valuetype_mask()) != 0;
+}
+
+inline bool Klass::ptr_is_value_type(Klass* v) {
+ return ((uintptr_t)v & KlassPtrValueTypeMask) != 0;
+}
+
 template <typename T>
 bool Klass::is_instanceof_or_null(T element) {
   if (oopDesc::is_null(element)) {