This patch contains changes to convert Ruby's stat handling to the M5-style Stat class. The ultimate goal is to remove Profiler entirely, though this patch only represents a (significant) step towards that goal. Some stats remain in the Profiler, notably those that do not have an obvious object to hold them (like Address Profiler) or those that I'm not sure what they do (e.g., *wCC*). Also, this patch does not contain a Garnet stats conversion (though the simple network is converted).