asn1_encode : x, y => 0 | x,0 | y
(because of DER encoding rules when x and y have high bit set)
CLA: Trivial
Reviewed-by: Paul Dale <paul.dale@oracle.com> Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6694)