8213236: A partial removed/deleted JavaThread cannot transition

Reviewed-by: dholmes, dcubed, eosterlund

src/hotspot/share/runtime/thread.cpp

@@ -4286,7 +4286,7 @@ bool Threads::destroy_vm() {
     // queue until after the vm thread is dead. After this point,
     // we'll never emerge out of the safepoint before the VM exits.
 
-    MutexLocker ml(Heap_lock);
+    MutexLockerEx ml(Heap_lock, Mutex::_no_safepoint_check_flag);
 
     VMThread::wait_for_vm_thread_exit();
     assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");