io-console.gemspec: drop 1.9
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42473 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
io-console.gemspec: drop 1.9
rb_cloexec_open() is mandatory now.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42473 b2dd03c8-39d4-4d8f-98ff-823fe69b080e