[Indic] Don't attach SM/VD to other characters

src/hb-ot-shape-complex-indic-private.hh

diff --git a/src/hb-ot-shape-complex-indic-private.hh b/src/hb-ot-shape-complex-indic-private.hh
index 5f4856e..4a4c8c0 100644
--- a/src/hb-ot-shape-complex-indic-private.hh
+++ b/src/hb-ot-shape-complex-indic-private.hh
@@ -83,6 +83,8 @@
 
 /* Visual positions in a syllable from left to right. */
 enum indic_position_t {
+  POS_START,
+
   POS_RA_TO_BECOME_REPH,
   POS_PRE_M,
   POS_PRE_C,
@@ -102,6 +104,7 @@
 
   POS_FINAL_C,
   POS_SMVD,
+
   POS_END
 };