does not handle `shadow` block "args"

[jaynetics]

str = 'a { |;a| }'
ast = RubyParser.new.parse(str)
# => s(:iter, s(:call, nil, :a), s(:args, s(:shadow, :a)))
Ruby2Ruby.new.process(ast)
# => RuntimeError (unknown arg type :shadow)

[zenspider]

Fixed. Thank you!