[libelftc] internal library or not?

Hi Ed, freebsd-current,

I want to add C++ demangling into sysutils/pstack. In man pages I've found
eltfc_demangle, exact what I need. This function belongs to libelftc. "make
installworld" installs man pages and include files, but there is no
installed library. As results compilation error is occuried.

In Makefile I've noticied line "INTERNALLIB=" which avoids installation of
".a" file. Commenting it allows to compile program, but I wonder what is
correct way to use elftc_demangle. Is elftoolchain internal and can't be
used by ports as all (i.e. man pages and include file to be removed from
world installation)?

Thank you in advance,
  Michael.