Sample usage:

./fzp < examples/aust.fzn | ./fz-paccs load name type code halt

Notes:

- AST nodes for fzn parser

TYPE : VALUE

- acceptable types:

- driver process fz-BACK (BACK is back-end specific):

reads stdin (as produced by bison-generated parser), which results
in a Prolog term which is the AST. It then does semantic analysis
(name & type).

AST is translated to an IR or actual C code for PaCCS.