Quite a lot of consumers of the SSL stack will never need to touch files from
the SSL stack, but enough do that we can't just ditch them. Toss that all into
their own file so a static linker can drop it.
Change-Id: Ia07de939889eb09e3ab16aebcc1b6869ca8b75a0
Reviewed-on: https://boringssl-review.googlesource.com/5820
Reviewed-by: Adam Langley <agl@google.com>
