PATCH for REVIEW: Move RegisterContextPOSIX to RegisterContextPOSIXProcessMonitor

Bit more RegisterContextPOSIX cleanup. This moves the RegisterContextPOSIX class to pure virtual and scoots it over directly to the RegisterContextPOSIXProcessMonitor classes. and removes it from the RegisterContextPOSIXCore classes which don’t use any of those functions. All that RegisterContextPOSIX breakpoint code gets moved to the ProcessMonitor classes also.

http://llvm-reviews.chandlerc.com/D1681

Thanks!
-Mike

The only thing I can think of is "RegisterContextPOSIX" now is just a mix-in protocol class and since it doesn't inherit from RegisterContext anymore, it might be better named something else? Maybe "POSIXBreakpointProtocol"?

Other than that, it looks good.