nl_types.h for tcsh build?

My attempt at building tcsh is failing due to a missing nl_types.h
(something about Native Language support). My RTP 6.1 system lacks this
and there does not seem to be a configure option to avoid it. So, what
dependency am I missing that Armin must have?

Also, I'm rebuilding because the tcsh binary complains frequently about
"Unmatched <x>" (x is some char from the command line) for each shell
command that I type in.

Lonnie.