[unicode7] Route Manichaean and Psalter Pahlavi through Arabic shaper

Still needs update to joining table to fully work.
diff --git a/src/hb-ot-shape-complex-private.hh b/src/hb-ot-shape-complex-private.hh
index 104726e..3e581af 100644
--- a/src/hb-ot-shape-complex-private.hh
+++ b/src/hb-ot-shape-complex-private.hh
@@ -173,6 +173,10 @@
     /* Unicode-6.0 additions */
     case HB_SCRIPT_MANDAIC:
 
+    /* Unicode-7.0 additions */
+    case HB_SCRIPT_MANICHAEAN:
+    case HB_SCRIPT_PSALTER_PAHLAVI:
+
       /* For Arabic script, use the Arabic shaper even if no OT script tag was found.
        * This is because we do fallback shaping for Arabic script (and not others). */
       if (planner->map.chosen_script[0] != HB_OT_TAG_DEFAULT_SCRIPT ||