instructions (e.g. "addl ref1,%eax" will be replaced by "addl %ebx,%eax"
if %ebx contains ref1). Previously only complete load sequences were
optimized away, but not such small accesses in other instructions than
mov/movzx/movsx
optimizer bugs with int64 calculations (because of the carry flag usage)
* fixed another bug which caused wrong optimizations with complex
array expressions
* 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
