Print thread name for attempting to unregister unattached thread

Bug: 18713034
Change-Id: Ic0654c6569277e5bbd6d2582140595faaa36cded
diff --git a/runtime/thread_list.cc b/runtime/thread_list.cc
index d0f014a..83c5ffb 100644
--- a/runtime/thread_list.cc
+++ b/runtime/thread_list.cc
@@ -1107,9 +1107,11 @@
     Locks::thread_list_lock_->ExclusiveLock(self);
     bool removed = true;
     if (!Contains(self)) {
+      std::string thread_name;
+      self->GetThreadName(thread_name);
       std::ostringstream os;
       DumpNativeStack(os, GetTid(), "  native: ", nullptr);
-      LOG(ERROR) << "Request to unregister unattached thread\n" << os.str();
+      LOG(ERROR) << "Request to unregister unattached thread " << thread_name << "\n" << os.str();
     } else {
       Locks::thread_suspend_count_lock_->ExclusiveLock(self);
       if (!self->IsSuspended()) {