- Removed flawed logic which assumed that sim_interval was meaningful when referenced by an asynchronous thread.
- Adjust the event_time of events removed from the asynch queue to account for the average time spent on the queue before the event was noticed by the instruction execution thread.
- Added a sim_activate_notbefore function which specifies an rtime which is the earliest time the event should fire.
- Changed the 'wakeup from idle' logic to force an immediate asynch queue check if the wakeup was not due to a timeout (i.e. it was due to an asynch queue insertion).
- Fixed the descrip.mms to build asynchronous support on AXP and IA64 VMS with kernel threads enabled