--- a/src/hotspot/share/runtime/thread.cpp	Fri Apr 05 07:10:07 2019 -0400
+++ b/src/hotspot/share/runtime/thread.cpp	Fri Apr 05 10:01:09 2019 +0100
@@ -3628,6 +3628,7 @@
   initialize_class(vmSymbols::java_lang_Thread(), CHECK);
   oop thread_object = create_initial_thread(thread_group, main_thread, CHECK);
   main_thread->set_threadObj(thread_object);
+
   // Set thread status to running since main thread has
   // been started and running.
   java_lang_Thread::set_thread_status(thread_object,
@@ -3636,6 +3637,15 @@
   // The VM creates objects of this class.
   initialize_class(vmSymbols::java_lang_Module(), CHECK);
 
+#ifdef ASSERT
+  InstanceKlass *k = SystemDictionary::UnsafeConstants_klass();
+  assert(k->is_not_initialized(), "UnsafeConstants should not already be initialized");
+#endif
+
+  // initialize the hardware-specific constants needed by Unsafe
+  initialize_class(vmSymbols::jdk_internal_misc_UnsafeConstants(), CHECK);
+  jdk_internal_misc_UnsafeConstants::set_unsafe_constants();
+
   // The VM preresolves methods to these classes. Make sure that they get initialized
   initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
   initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);