set_local_type

Parse one type declaration and store it in the specified slot
     ordinal -  slot number (1...NumberOfLocalTypes)
                -1 means allocate new slot or reuse the slot
                of the existing named type
     input -  C declaration. Empty input empties the slot
     flags -  combination of PT_... constants or 0
returns: slot number or 0 if error

success set_local_type(long ordinal, string input, long flags);