Is there a Right Way to include RCS ids in code that can be built
both for kernel and userland?  I notice there are two macros, so does
that mean

#ifdef _KERNEL
__KERNEL_RCSID(0,"foo");
#else
__RCSID("foo");
#endif

?

I don't see it done in existing code, but common/lib/libc uses
plain __RCSID unconditionally, and common/lib/libprop uses no
RCS ids at all, so I'm not sure what lesson to take away.

-Chap