Open3.capture3, Open3.capture2, Open3.capture2e accepts
IO-like object for :stdin_data argument.
[ruby-core:80936] [Feature #13527] proposed by janko.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60236 b2dd03c8-39d4-4d8f-98ff-823fe69b080e