It seems that the inclusion of "pmap_rmt.h" is
not right. The definitions there are not directly
mentioned in the manpage, and where they are
needed (libc/rpc/pmap_rmt.c) this file is included
explicitely.
With "pmap_rmt.h", we get collisions in the
portmapper hisself - it has the "other ends" of
the conversion functions, with identic names.
It's of course easy to change the portmapper used
names, but I've got the impression that "pmap_rmt.h"
is for library internal use only.

best regards
Matthias