qapi: Generate in source order

The generators' conversion to visitors (merge commit 9e72681d16)
changed the processing order of entities from source order to
alphabetical order.  The next commit needs source order, so change it
back.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180211093607.27351-17-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

scripts/qapi/common.py

@@ -1474,6 +1474,7 @@ class QAPISchema(object):
         parser = QAPISchemaParser(open(fname, 'r'))
         exprs = check_exprs(parser.exprs)
         self.docs = parser.docs
+        self._entity_list = []
         self._entity_dict = {}
         self._predefining = True
         self._def_predefineds()
@@ -1485,6 +1486,7 @@ class QAPISchema(object):
         # Only the predefined types are allowed to not have info
         assert ent.info or self._predefining
         assert ent.name not in self._entity_dict
+        self._entity_list.append(ent)
         self._entity_dict[ent.name] = ent
 
     def lookup_entity(self, name, typ=None):
@@ -1683,12 +1685,12 @@ class QAPISchema(object):
                 assert False
 
     def check(self):
-        for (name, ent) in sorted(self._entity_dict.items()):
+        for ent in self._entity_list:
             ent.check(self)
 
     def visit(self, visitor):
         visitor.visit_begin(self)
-        for (name, entity) in sorted(self._entity_dict.items()):
+        for entity in self._entity_list:
             if visitor.visit_needed(entity):
                 entity.visit(visitor)
         visitor.visit_end()