* bignum.c: An static assertion for relation of SIZEOF_LONG and
  SIZEOF_BDIGITS is added.
  (bary_mul_precheck): Reduce comparisons.
  (bary_mul): Invoke bary_sq_fast or bary_mul1 if the bignum size is
  small.
  (bigfixize): Resize the argument bignum here.
  (bignorm): Don't call bigtrunc after bigfixize.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42028 b2dd03c8-39d4-4d8f-98ff-823fe69b080e