From: Wayne Scott <wscott / ichips.intel.com>
> Well actually, 0xbabe[8,8] returns 0xba.  The bits start counting at
> zero and go up.  I design processors and write scripts that mess with
> bit fields all the time.
> 
> desc[36,4] = DATA_SEGMENT


I just realized that the '[]=' is not implimented for Fixnum and Bignum.
Add that to my feature request. :)

There is no reason we just be able to write bitfields as well.  I will
try to write a patch if people (and Matz) like the feature.  I have been
wanting to learn Ruby internals.

-Wayne