(COMPARE_AND_EXCHANGE): Create safe version.  Note that is use MIPS II instructions ll/sc and does not work on R3000.
(COMPARE_AND_EXCHANGE): Create safe version.  Note that is use MIPS II
instructions ll/sc and does not work on R3000.

kaffe/kaffe,kaffe/kaffe,kaffe/kaffe,kaffe/kaffe,kaffe/kaffe