* changed command line options meanings for optimizer:
O2 now means peepholopts, CSE and register renaming in 1 pass
O3 is the same, but repeated until no further optimizations are
possible or until 5 passes have been done (to avoid endless loops)
* changed aopt386 so it does this looping
* added some procedures from csopt386 to the interface because they're
used by rropt386 as well
* some changes to csopt386 and daopt386 so that newly added instructions
by the CSE get optimizer info (they were simply skipped previously),
this fixes some bugs
