--- old/src/hotspot/share/gc/z/zPageAllocator.hpp	2017-12-21 17:35:43.939261849 +0900
+++ new/src/hotspot/share/gc/z/zPageAllocator.hpp	2017-12-21 17:35:43.804259574 +0900
@@ -36,6 +36,8 @@
 class ZPageAllocRequest;
 
 class ZPageAllocator VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
 private:
   ZLock                    _lock;
   ZVirtualMemoryManager    _virtual;