Closer-to-working invoke dynamic lambdas

  - adjust to flipped captured/lambda parameter group order
    in the body of the old-school anonymous function lambda
  - Replace `<<load args>>; new anon$fun; <init>`
         by `<<load args>>; invokedynamic`
    rather than just the `<init>` call. Fixes verify errors.
  - Unhardcode types and arity.
Don't emit the old-school function in GenBCode