Add ids to flatbuffer fields in y2012, y2016, frc971, and aos

Change-Id: I9ed9006ce6224e2df0459df47771786b928164a1
diff --git a/y2016/control_loops/superstructure/superstructure_position.fbs b/y2016/control_loops/superstructure/superstructure_position.fbs
index fb356e0..3660e43 100644
--- a/y2016/control_loops/superstructure/superstructure_position.fbs
+++ b/y2016/control_loops/superstructure/superstructure_position.fbs
@@ -11,9 +11,9 @@
   // the shooter wheels pointed towards the shoulder joint.  This is measured
   // relative to the arm, not the ground, not like the world we actually
   // present to users.
-  intake:frc971.PotAndIndexPosition;
-  shoulder:frc971.PotAndIndexPosition;
-  wrist:frc971.PotAndIndexPosition;
+  intake:frc971.PotAndIndexPosition (id: 0);
+  shoulder:frc971.PotAndIndexPosition (id: 1);
+  wrist:frc971.PotAndIndexPosition (id: 2);
 }
 
 root_type Position;