• Added: Type::Params now has a goto_next option, which if set to a
  coderef will generate a signature which on success, instead of returning
  @, passes @ to the coderef. If goto_next is set to true, the
  signature instead expects to be passed such a coderef as its first
  argument.
  
• Eval::TypeTiny::CodeAccumulator now better handles placeholders.
  
• Type::Params wrap_subs and wrap_methods internally use goto_next.