This differs from a plain old comment in the following ways:
1. It is optionally macro-expanded;
2. It has a dash prefix;
3. It can be used inside .nolist macros.
Suggested-by: <pushbx@ulukai.org>
Resolves: https://bugzilla.nasm.us/show_bug.cgi?id=3392915
Signed-off-by: H. Peter Anvin <hpa@zytor.com>