1. Go back to the way things were -- __consttime_bcmp/__explicit_bzero
in libc, consttime_bcmp/explicit_bzero in kernel, and move the man
pages into section 9 -- against christos's objection.
2. Use __consttime_memequal/__explicit_memset in userland,
consttime_memequal/explicit_memset in kernel, and move the man pages
into section 9.
3. Use consttime_memequal/explicit_memset in userland and kernel,
expose them as a public part of libc, and keep the man pages in
section 3. This would presumably require the rigamarole of making the
libc symbols weak with internal namespacing wotsits.