* bignum.c: Don't hard code SIZEOF_BDIGITS for log_base(hbase).
  (big2str_orig): hbase_numdigits argument added.
  (big2str_karatsuba): Ditto.
  (rb_big2str0): Calculate hbase_numdigits.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41004 b2dd03c8-39d4-4d8f-98ff-823fe69b080e