Added a new packet to our GDB remote protocol:

	QListThreadsInStopReply
	
This GDB remote query command can enable added a "threads" key/value pair to all stop reply packets so that we always get a list of all threads in each stop reply packet. It increases performance if enabled (the reply to the "QListThreadsInStopReply" is "OK") by saving us from sending to command/reply pairs (the "qfThreadInfo" and "qsThreadInfo" packets), and also helps us keep the current process state up to date. 

llvm-svn: 154380