Reduce churn in the future patch that replaces anonymous unions
with a new metatype 'alternate' by changing 'AnonUnion' to
'Alternate'.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>