Better -x handling.  If the language defines the standard port parameters but doesn't bind them, we bind them to stdin/stdout/stderr. If the parameters are not defined at all, we abort.
Better -x handling.  If the language defines the standard port
parameters but doesn't bind them, we bind them to stdin/stdout/stderr.
If the parameters are not defined at all, we abort.

traviscross/chibi-scheme,traviscross/chibi-scheme,traviscross/chibi-scheme,traviscross/chibi-scheme