using multiple passes. Fixes RubyGems bug #422. Refactored for maintainability. * test/rubygems/test_gem_commands_cleanup_command.rb: Test for above. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38698 b2dd03c8-39d4-4d8f-98ff-823fe69b080e