On FreeBSD, threads don't die on daemon(3)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41903 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-07-11

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41904 b2dd03c8-39d4-4d8f-98ff-823fe69b080e