I needed the attached patch on top of the bptest patch for the current
code.  Btw, that is a very nice little tester!

Below that is a patch to go on top of your current patch, with x86-64
support.  I've only tried a few trivial tests with bptest (including an
8-byte bp), which worked great.  It is a pretty faithful copy of your i386
changes.  I'm still not sure we have all that right, but you might as well
incorporate this into your patch.  You should change the x86_64 code in
parallel with any i386 changes we decide on later, and I can test it and
send you any typo fixups or whatnot.


Thanks,
Roland