Put sys-specific files in build.info

Put sys-specific files in build.info

Don't wrap whole files in if[n]def, test in build.info if they
should be compiled.  rand_win isn't done as there are multiple
ways to say "this is windows."

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11263)