Add specs on destructuring assignment on object with private #to_a.
Add specs on Kernel#Array on objects with private #to_ary.
Add specs on Kernel#Array on objects with private #to_a.
Add specs on Rubinius::Type#check_convert_type on objects with private methods.
Add specs on Array#initialize on objects with private #to_ary.
Coercing to array via #to_a also works when it's private.
Start to look up methods for dispatching from private visibility.
Array#initialize: coerce object parameter to array works when #to_ary is private.
Rubinius::Type.check_convert_type: detect coercing method also when it's private.
Kernel#Array: coerce object parameter to array works when #to_a is private.