* benchmark/bm_require_thread.rb: new benchmark for conflicting
require vs thread. like [Bug #11559]
* prepare_require.rb: new file for preparing above tests.
* prepare_require.rb: ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
kosaki