New enum QapiSpecialFeature enumerates the special feature flags.
New helper gen_special_features() returns code to represent a
collection of special feature flags as a bitset.
The next few commits will put them to use.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20211028102520.747396-5-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
c67db1ed16