[dns-operations] Wildcard label as CNAME target seen in the wild

[Florian Weimer]

* Viktor Dukhovni:

> Would you care to list which applications you observed to refuse
> to accept this edge-case?

All of them, when running on GNU/Linux?  glibc has a bug where it does
not accept such names:

  <https://sourceware.org/bugzilla/show_bug.cgi?id=12154>

Thanks,
Florian