* bignum.c (get2comp): Use bary_2comp.
  (abs2twocomp_bang): New function.
  (abs2twocomp): New function.
  (twocomp2abs_bang): New function.
  (rb_big_and): Use abs2twocomp and twocomp2abs_bang.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41680 b2dd03c8-39d4-4d8f-98ff-823fe69b080e