Use ny instead of RBIGNUM_LEN(y).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41281 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_fileutils.rb: parents option

* test/fileutils/test_fileutils.rb (TestFileUtils#test_rmdir): add
  assertions for parents option.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41282 b2dd03c8-39d4-4d8f-98ff-823fe69b080e