* bignum.c (big2ulong): Add a cast.
  (big2ull): Add a specialized code for SIZEOF_LONG_LONG <=
  SIZEOF_BDIGITS.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41618 b2dd03c8-39d4-4d8f-98ff-823fe69b080e