* bignum.c (bigfixize): Use rb_absint_size.
  (check_shiftdown): Ditto.
  (big2ulong): Use bdigit_roomof.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41435 b2dd03c8-39d4-4d8f-98ff-823fe69b080e