Rubinius splat with **options bug

rbx-bug.rb

class Outer
  def initialize(*args, **options)
    raise ArgumentError, "args should be an array of a String, was #{args.inspect}" if args.first.is_a?(Array)
  end
end

class Inner < Outer
  def initialize(*args, **options)
    super
  end
end

Inner.new("foo", bar: :baz)

stack-trace.txt

$ rbx rbx-bug.rb
An exception occurred running rbx-bug.rb

args should be an array of a String, was [["foo"], "foo"] (ArgumentError)

Backtrace:

           Outer(Inner)#initialize at rbx-bug.rb:3
                  Inner#initialize at rbx-bug.rb:9
                 Object#__script__ at rbx-bug.rb:13
  Rubinius::CodeLoader#load_script at kernel/delta/code_loader.rb:66
  Rubinius::CodeLoader.load_script at kernel/delta/code_loader.rb:152
           Rubinius::Loader#script at kernel/loader.rb:656
             Rubinius::Loader#main at kernel/loader.rb:842