Attach a "foreign" thread to NSPR as a "system" thread so that...

third_party/nss/mozilla/nsprpub/pr/src/md/windows/w95thred.c

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
@@ skipping 291 matching lines @@
 
 PRThread*
 _MD_CURRENT_THREAD(void)
 {
 PRThread *thread;
 
         thread = _MD_GET_ATTACHED_THREAD();
 
         if (NULL == thread) {
                 thread = _PRI_AttachThread(
-            PR_USER_THREAD, PR_PRIORITY_NORMAL, NULL, 0);
+            PR_SYSTEM_THREAD, PR_PRIORITY_NORMAL, NULL, 0);
         }
         PR_ASSERT(thread != NULL);
         return thread;
 }
 
 // The following code is from Chromium src/base/thread_local_storage_win.cc,
 // r11329.
 
 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 //
@@ skipping 91 matching lines @@
 
 #else  // _WIN64
 
 #pragma data_seg(".CRT$XLB")
 PIMAGE_TLS_CALLBACK p_thread_callback = PR_OnThreadExit;
 
 // Reset the default section.
 #pragma data_seg()
 
 #endif  // _WIN64