we don't want to expose but which can't or shouldn't be static.
To mark a library as private, define PRIVATELIB in its Makefile. It
will be installed in LIBPRIVATEDIR, which is normally /usr/lib/private
(or /usr/lib32/private for 32-bit libraries on 64-bit platforms).
To indicate that a program or library depends on a private library,
define USEPRIVATELIB in its Makefile. The correct version of
LIBPRIVATEDIR will be added to its run-time library search path.
Approved by: re (blanket)