The old code prints the result of parsing (list of expression
dictionaries), and partial results of semantic analysis (list of enum
dictionaries, list of struct dictionaries).

The new code prints a trace of a schema visit, i.e. what the back-ends
are going to use.  Built-in and array types are omitted, because
they're boring.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>