shallow: migrate shallow information into the object parser

We need to convert the shallow functions all at the same time
as we move the data structures they operate on into the repository.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

object.c

@@ -464,6 +464,9 @@ struct parsed_object_pool *parsed_object_pool_new(void)
 	o->tag_state = allocate_alloc_state();
 	o->object_state = allocate_alloc_state();
 
+	o->is_shallow = -1;
+	o->shallow_stat = xcalloc(1, sizeof(*o->shallow_stat));
+
 	return o;
 }