This change adds two functions to cryptobyte to encode and decode int64 with tags supplied by the user. This change also modifies a documentation comment which was outdated. Fixes golang/go#24973 Change-Id: I2e3ca475891ba62df902f33085719f94e87a27cc GitHub-Last-Rev: cd0300d9bfbd4e38f22503a046ea18f9ddd37676 GitHub-Pull-Request: golang/crypto#42 Reviewed-on: https://go-review.googlesource.com/108456 Reviewed-by: Adam Langley <agl@golang.org>