CBB_add_asn1_uint64 doesn't work if you're encoding an implicitly-tagged INTEGER. Take a leaf from Go cryptobyte and add a "with tag" variant, rather than a "contents" variant, which is a little more convenient to use. It also avoids us having to decide how to name the contents field. Change-Id: I6072e55017230c513577c44c5a7ed86e778255b3 Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/54685 Reviewed-by: Bob Beck <bbe@google.com> Commit-Queue: Bob Beck <bbe@google.com> Commit-Queue: David Benjamin <davidben@google.com> Auto-Submit: David Benjamin <davidben@google.com>