[indic] Rename avagraha cluster to symbol cluster

In anticipation of adding more characters to that class of clusters.

src/hb-ot-shape-complex-indic-machine.rl

diff --git a/src/hb-ot-shape-complex-indic-machine.rl b/src/hb-ot-shape-complex-indic-machine.rl
index 5e28843..c64c03e 100644
--- a/src/hb-ot-shape-complex-indic-machine.rl
+++ b/src/hb-ot-shape-complex-indic-machine.rl
@@ -56,7 +56,7 @@
 Repha = 15;
 Ra    = 16;
 CM    = 17;
-Avag  = 18;
+Symbol= 18;
 CM2   = 31;
 
 c = (C | Ra);			# is_consonant
@@ -67,10 +67,10 @@
 
 cn = c.ZWJ?.n?;
 forced_rakar = ZWJ H ZWJ Ra;
-avagraha = Avag.N?;
+symbol = Symbol.N?;
 matra_group = z{0,3}.M.N?.(H | forced_rakar)?;
 syllable_tail2 = (SM.SM?.ZWNJ?)? A{0,3}? VD{0,2};
-syllable_tail =  (Coeng (cn|V))? avagraha? syllable_tail2;
+syllable_tail =  (Coeng (cn|V))? symbol? syllable_tail2;
 place_holder = NBSP | DOTTEDCIRCLE;
 halant_group = (z?.h.(ZWJ.N?)?);
 final_halant_group = halant_group | h.ZWNJ;
@@ -81,7 +81,7 @@
 consonant_syllable =	Repha? (cn.halant_group){0,4} cn medial_group halant_or_matra_group syllable_tail;
 vowel_syllable =	reph? V.n? (ZWJ | (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail);
 standalone_cluster =	reph? place_holder.n? (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail;
-avagraha_cluster = 	avagraha syllable_tail2;
+symbol_cluster = 	symbol syllable_tail2;
 broken_cluster =	reph? n? (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail;
 other =			any;
 
@@ -89,7 +89,7 @@
 	consonant_syllable	=> { found_syllable (consonant_syllable); };
 	vowel_syllable		=> { found_syllable (vowel_syllable); };
 	standalone_cluster	=> { found_syllable (standalone_cluster); };
-	avagraha_cluster	=> { found_syllable (avagraha_cluster); };
+	symbol_cluster		=> { found_syllable (symbol_cluster); };
 	broken_cluster		=> { found_syllable (broken_cluster); };
 	other			=> { found_syllable (non_indic_cluster); };
 *|;

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 3de5c20..fe8b207 100644
--- a/src/hb-ot-shape-complex-indic-private.hh
+++ b/src/hb-ot-shape-complex-indic-private.hh
@@ -60,7 +60,7 @@
   OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
   OT_Ra = 16,
   OT_CM = 17,  /* Consonant-Medial. */
-  OT_Avag = 18, /* Avagraha. */
+  OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
   OT_CM2 = 31 /* Consonant-Medial, second slot. */
 };
 
@@ -95,7 +95,7 @@
 enum indic_syllabic_category_t {
   INDIC_SYLLABIC_CATEGORY_OTHER			= OT_X,
 
-  INDIC_SYLLABIC_CATEGORY_AVAGRAHA		= OT_Avag,
+  INDIC_SYLLABIC_CATEGORY_AVAGRAHA		= OT_Symbol,
   INDIC_SYLLABIC_CATEGORY_BINDU			= OT_SM,
   INDIC_SYLLABIC_CATEGORY_CONSONANT		= OT_C,
   INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD	= OT_C,

src/hb-ot-shape-complex-indic.cc

diff --git a/src/hb-ot-shape-complex-indic.cc b/src/hb-ot-shape-complex-indic.cc
index c20ffd0..89fc46c 100644
--- a/src/hb-ot-shape-complex-indic.cc
+++ b/src/hb-ot-shape-complex-indic.cc
@@ -271,7 +271,7 @@
   {
     pos = matra_position (u, pos);
   }
-  else if ((FLAG (cat) & (FLAG (OT_SM) | FLAG (OT_VD) | FLAG (OT_A) | FLAG (OT_Avag))))
+  else if ((FLAG (cat) & (FLAG (OT_SM) | FLAG (OT_VD) | FLAG (OT_A) | FLAG (OT_Symbol))))
   {
     pos = POS_SMVD;
   }
@@ -639,7 +639,7 @@
   consonant_syllable,
   vowel_syllable,
   standalone_cluster,
-  avagraha_cluster,
+  symbol_cluster,
   broken_cluster,
   non_indic_cluster,
 };
@@ -1207,10 +1207,10 @@
 }
 
 static void
-initial_reordering_avagraha_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
-				     hb_face_t *face HB_UNUSED,
-				     hb_buffer_t *buffer HB_UNUSED,
-				     unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
+initial_reordering_symbol_cluster (const hb_ot_shape_plan_t *plan HB_UNUSED,
+				   hb_face_t *face HB_UNUSED,
+				   hb_buffer_t *buffer HB_UNUSED,
+				   unsigned int start HB_UNUSED, unsigned int end HB_UNUSED)
 {
   /* Nothing to do right now.  If we ever switch to using the output
    * buffer in the reordering process, we'd need to next_glyph() here. */
@@ -1238,7 +1238,7 @@
   case consonant_syllable:	initial_reordering_consonant_syllable (plan, face, buffer, start, end); return;
   case vowel_syllable:		initial_reordering_vowel_syllable     (plan, face, buffer, start, end); return;
   case standalone_cluster:	initial_reordering_standalone_cluster (plan, face, buffer, start, end); return;
-  case avagraha_cluster:	initial_reordering_avagraha_cluster   (plan, face, buffer, start, end); return;
+  case symbol_cluster:		initial_reordering_symbol_cluster     (plan, face, buffer, start, end); return;
   case broken_cluster:		initial_reordering_broken_cluster     (plan, face, buffer, start, end); return;
   case non_indic_cluster:	initial_reordering_non_indic_cluster  (plan, face, buffer, start, end); return;
   }