dump: Add parsing of thread pids

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

include/crtools.h

@@ -89,6 +89,8 @@ struct pstree_item {
 	struct list_head	list;
 	pid_t			pid;		/* leader pid */
 	u32			nr_children;	/* number of children */
+	u32			nr_threads;	/* number of threads */
+	u32			*threads;	/* array of threads */
 	u32			*children;	/* array of children */
 };