* To the F77 and F2003 interface generators that is.

* The previous implementation would enter an infinite loop if a
  comment containing only whitespace occurred (e.g. /*   */).

* Always return the ID of the unpacked resource.

* This enables the use of vector instructions for initializations.

* xyz can only be one of 123, 132, 213, 231, 312, 321.

* vlist_to_pointer cannot return a NULL pointer.

* The modulo result is available on most architectures in a register
  anyway.