vgrind with c, TROFF=nroff

[Richard O'Keefe]

Context: vgrind on a Sun-3/50 running Export SunOS 4.0.something.

	% setenv TROFF nroff
	% vgrind -lc -t someprog.c

Why the setenv?  Two reasons:  (a) troff on this particular machine complains
about some font or other that it can't find, and (b) I like to "proof" things
on the screen before sending garbage to the printer.

Problem: the text that's written to the screen has hyphens where the input
had underscores.  E.g. if the input had PANEL_FEATURE the output has
PANEL-FEATURE.

Question: is vgrind supposed to do this?  Is there a way to stop it?