Boost线程:在IOS中，在线程执行完成之前，会对thread_info对象进行销毁

Our project uses a few boost 1.48 libraries on several platforms, including Windows, Mac, Android, and IOS. We are able to consistently get the IOS version of the project to crash (nontrivially but reliably) when using IOS, and from our investigation we see that ~thread_data_base is being called on the thread's thread_info while its thread is still running.Our project uses a few boost 1.48 libraries on