Don't lock the IOHandlerList::m_mutex in Debugger::RunIOHandler(...) since if a process is resumed or halted, it will try to push/pop the process IOHandler and it will deadlock.

<rdar://problem/18610852>



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@219620 91177308-0d34-0410-b5e6-96231b3b80d8