[indic-like] Move allocation of syllable() buffer var to shapers that use it

In indic, we don't have a pause location release the var.

src/hb-ot-layout.cc

@@ -260,7 +260,6 @@ _hb_ot_layout_set_glyph_props (hb_font_t *font,
   {
     _hb_glyph_info_set_glyph_props (&buffer->info[i], gdef.get_glyph_props (buffer->info[i].codepoint));
     _hb_glyph_info_clear_lig_props (&buffer->info[i]);
-    buffer->info[i].syllable() = 0;
   }
 }
 

src/hb-ot-layout.hh

@@ -589,13 +589,11 @@ _hb_buffer_allocate_gsubgpos_vars (hb_buffer_t *buffer)
 {
   HB_BUFFER_ALLOCATE_VAR (buffer, glyph_props);
   HB_BUFFER_ALLOCATE_VAR (buffer, lig_props);
-  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
 }
 
 static inline void
 _hb_buffer_deallocate_gsubgpos_vars (hb_buffer_t *buffer)
 {
-  HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
   HB_BUFFER_DEALLOCATE_VAR (buffer, lig_props);
   HB_BUFFER_DEALLOCATE_VAR (buffer, glyph_props);
 }
@@ -605,7 +603,6 @@ _hb_buffer_assert_gsubgpos_vars (hb_buffer_t *buffer)
 {
   HB_BUFFER_ASSERT_VAR (buffer, glyph_props);
   HB_BUFFER_ASSERT_VAR (buffer, lig_props);
-  HB_BUFFER_ASSERT_VAR (buffer, syllable);
 }
 
 /* Make sure no one directly touches our props... */

src/hb-ot-shaper-indic.cc

@@ -356,6 +356,7 @@ setup_syllables_indic (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		       hb_font_t *font HB_UNUSED,
 		       hb_buffer_t *buffer)
 {
+  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
   find_syllables_indic (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);

src/hb-ot-shaper-khmer.cc

@@ -115,7 +115,7 @@ collect_features_khmer (hb_ot_shape_planner_t *plan)
     map->add_feature (khmer_features[i]);
 
   /* https://github.com/harfbuzz/harfbuzz/issues/3531 */
-  map->add_gsub_pause (nullptr);
+  map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
 
   for (; i < KHMER_NUM_FEATURES; i++)
     map->add_feature (khmer_features[i]);
@@ -187,6 +187,7 @@ setup_syllables_khmer (const hb_ot_shape_plan_t *plan HB_UNUSED,
 		       hb_font_t *font HB_UNUSED,
 		       hb_buffer_t *buffer)
 {
+  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
   find_syllables_khmer (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);

src/hb-ot-shaper-myanmar.cc

@@ -92,6 +92,7 @@ collect_features_myanmar (hb_ot_shape_planner_t *plan)
     map->enable_feature (myanmar_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
     map->add_gsub_pause (nullptr);
   }
+  map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
 
   for (unsigned int i = 0; i < ARRAY_LENGTH (myanmar_other_features); i++)
     map->enable_feature (myanmar_other_features[i], F_MANUAL_ZWJ);
@@ -118,6 +119,7 @@ setup_syllables_myanmar (const hb_ot_shape_plan_t *plan HB_UNUSED,
 			 hb_font_t *font HB_UNUSED,
 			 hb_buffer_t *buffer)
 {
+  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
   find_syllables_myanmar (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);

src/hb-ot-shaper-syllabic.cc

@@ -99,5 +99,13 @@ hb_syllabic_insert_dotted_circles (hb_font_t *font,
   buffer->sync ();
 }
 
+HB_INTERNAL void
+hb_syllabic_clear_var (const hb_ot_shape_plan_t *plan,
+		       hb_font_t *font,
+		       hb_buffer_t *buffer)
+{
+  HB_BUFFER_DEALLOCATE_VAR (buffer, syllable);
+}
+
 
 #endif

src/hb-ot-shaper-syllabic.hh

@@ -38,5 +38,10 @@ hb_syllabic_insert_dotted_circles (hb_font_t *font,
 				   int repha_category = -1,
 				   int dottedcircle_position = -1);
 
+HB_INTERNAL void
+hb_syllabic_clear_var (const hb_ot_shape_plan_t *plan,
+		       hb_font_t *font,
+		       hb_buffer_t *buffer);
+
 
 #endif /* HB_OT_SHAPER_SYLLABIC_HH */

src/hb-ot-shaper-use.cc

@@ -133,6 +133,7 @@ collect_features_use (hb_ot_shape_planner_t *plan)
     map->enable_feature (use_basic_features[i], F_MANUAL_ZWJ | F_PER_SYLLABLE);
 
   map->add_gsub_pause (reorder_use);
+  map->add_gsub_pause (hb_syllabic_clear_var); // Don't need syllables anymore, use stop to free buffer var
 
   /* "Topographical features" */
   for (unsigned int i = 0; i < ARRAY_LENGTH (use_topographical_features); i++)
@@ -297,6 +298,7 @@ setup_syllables_use (const hb_ot_shape_plan_t *plan,
 		     hb_font_t *font HB_UNUSED,
 		     hb_buffer_t *buffer)
 {
+  HB_BUFFER_ALLOCATE_VAR (buffer, syllable);
   find_syllables_use (buffer);
   foreach_syllable (buffer, start, end)
     buffer->unsafe_to_break (start, end);