functions. Code contributed by Aleksey Cheusov in PR#36394, and slightly
tweaked for closer-to-KNF conventions by me. Also slightly improved checks
of error returns.
This is the original New AWK from AT&T Labs as described in "The
AWK Programming Language", by Al Aho, Brian Kernighan, and Peter
Weinberger.
This would eventually replace gawk in our tree in future.