* bignum.c (rb_absint_singlebit_p): Use POW2_P.
  (bary_pack): Ditto.
  (rb_big2str0): Ditto.
  (POW2_P): Moved to top.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41630 b2dd03c8-39d4-4d8f-98ff-823fe69b080e