Add specs for top-level return (tested with Ruby 2.4.2)
Add specs for top-level return (tested with Ruby 2.4.2)

ruby/spec,ruby/spec,ruby/spec,eregon/rubyspec,eregon/rubyspec,ruby/rubyspec,nobu/rubyspec,ruby/rubyspec,nobu/rubyspec,eregon/rubyspec,nobu/rubyspec