Get initial thread state coordinator integration working.
- Fixed bug in run loop where run loop return enum was being treated erroneously like an int, causing the TSC event loop to terminate prematurely.
- Added an explicit scope in NativeProcessLinux::Resume() for the threads lock lifetime. (This was likely unnecessary but is more explicit.)
- Fixed a bug in ThreadStateCoordinator where resume execution was not updating the internal state about the thread assumed to be running now. I'll add a test and upstream this in a moment.
- Added a verbose logging mechanism to event processing within ThreadStateCoordinator. It is currently enabled when the 'log enable lldb thread' is true upon inferior launch/attach.