Create a new header lwp_private.h to contain _lwp_getprivate_fast,
_lwp_gettcb_fast, _lwp_settcb and remove them from mcontext.h, so that:
1. we don't need special hacks to hide them
2. we can include <lwp.h> where needed to get the necessary prototypes
without redefining them locally.

distrib/sets/lists: Add a blank comment line between RCS id and body.

This serves as a buffer between RCS id changes and other changes to
the set lists, in an attempt to reduce the pain of merge conflicts
around mass set list changes.

No functional change intended.

branches: 1.1.2;
First cut at set list for virt68k.