reapi: add accessors for traverser pre/post order count

Problem: new resource query and potentially other tools using this
api may need access to the traverser pre and post order counts.
Accessors for these fields do not exist.

Create accessors for these fields in reapi_cli_t and
resource_query_t.

resource/reapi/bindings/c++/reapi_cli.hpp

@@ -72,6 +72,8 @@ class resource_query_t {
     const std::shared_ptr<job_info_t> &get_job (const uint64_t jobid);
     const bool reservation_exists (const uint64_t jobid);
     const bool allocation_exists (const uint64_t jobid);
+    const unsigned int preorder_count ();
+    const unsigned int postorder_count ();
 
     /* Mutators */
     void clear_resource_query_err_msg ();
@@ -142,7 +144,9 @@ class reapi_cli_t : public reapi_t {
     static int info (void *h, const uint64_t jobid, std::string &mode,
                      bool &reserved, int64_t &at, double &ov);
     static int info (void *h, const uint64_t jobid,
-                     std::shared_ptr<job_info_t> &job); 
+                     std::shared_ptr<job_info_t> &job);
+    static unsigned int preorder_count (void *h);
+    static unsigned int postorder_count (void *h);
     static int stat (void *h, int64_t &V, int64_t &E,int64_t &J,
                      double &load, double &min, double &max, double &avg);
     static const std::string &get_err_message ();

resource/reapi/bindings/c++/reapi_cli_impl.hpp

@@ -263,6 +263,20 @@ int reapi_cli_t::info (void *h, const uint64_t jobid,
     return 0;
 }
 
+unsigned int reapi_cli_t::preorder_count (void *h)
+{
+    resource_query_t *rq = static_cast<resource_query_t *> (h);
+
+    return rq->preorder_count ();
+}
+
+unsigned int reapi_cli_t::postorder_count (void *h)
+{
+    resource_query_t *rq = static_cast<resource_query_t *> (h);
+
+    return rq->postorder_count ();
+}
+
 int reapi_cli_t::stat (void *h, int64_t &V, int64_t &E,int64_t &J,
                        double &load, double &min, double &max, double &avg)
 {
@@ -634,6 +648,16 @@ const bool resource_query_t::reservation_exists (const uint64_t jobid)
     return reservations.find (jobid) != reservations.end ();
 }
 
+const unsigned int resource_query_t::preorder_count ()
+{
+    return traverser->get_total_preorder_count ();
+}
+
+const unsigned int resource_query_t::postorder_count ()
+{
+    return traverser->get_total_postorder_count ();
+}
+
 void resource_query_t::clear_resource_query_err_msg ()
 {
     m_err_msg = "";