Ruby

• lib/test/unit.rb (Test::Unit::Runner#_run_parallel): no need to
  retry skipped test. this fix makes 40% faster the whole test-all
  with -j5 on Windows.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38257 b2dd03c8-39d4-4d8f-98ff-823fe69b080e