DEK132895
Code introduced into V5.1A BL24 (PK6) and V5.1B BL24 (PK3) to prevent 
an aio-related application deadlock has the potential to increase 
contention for the map lock.  This lock contention could severely reduce 
aio throughput. 


DSATD1ZVW
Provide a new closef() analogue for use by aio which would not call VOP_LOCKCTL to release file region locks.




