Integer fixes for Mantis 6987

 
I have updated the SqueakSource VMMaker project (VMMaker-dtl.117)
with fixes from Mantis 6987.

  http://bugs.squeak.org/view.php?id=6987
  http://www.squeaksource.com/VMMaker/VMMaker-dtl.117.mcz

I believe these fixes are correct for the 32 and 64-bit integer
methods, and I verified them on both 32 and 64-bit images. However,
I have not run the Alien tests, and I did not run the FFITestCase.st
test on Mantis (I don't have a 32-bit machine handy at the moment).
If anyone has a chance to validate these changes with the Alien
tests, please let me know (or just close the issue on Mantis if
it is complete).

Dave