* test/fileutils/test_fileutils.rb (test_ln_s): skip if symlink is not
available.
* test/fileutils/test_fileutils.rb (test_ln_s): remove created symlink
certainly.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58726 b2dd03c8-39d4-4d8f-98ff-823fe69b080e