Ruby

• lib/ostruct.rb: Finish defining OpenStruct attributes lazily.
  Patch by @sferik in [GH-1037]: https://github.com/ruby/ruby/pull/1037
  This commit is an addendum to https://github.com/ruby/ruby/pull/1033.
  It:
  1. lazily defines attribute accessors for copied and marshaled objects,
  2. returns nil when an attribute reader is not defined, and
  3. defines respond_to_missing? to maintain the same respond_to? behavior

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52125 b2dd03c8-39d4-4d8f-98ff-823fe69b080e