[indic] Apply calt,clig in the same stage as presentation features

Whic means these twp are applied per-syllable now.  Apparently
in some Khmer fonts the clig interacts with presentation features.

Test case: U+1781,U+17D2,U+1789,U+17BB,U+17C6 with Mondulkiri-R.ttf
should produce one big ligature.

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

@@ -447,6 +447,10 @@ collect_features_indic (hb_ot_shape_planner_t *plan)
   for (; i < INDIC_NUM_FEATURES; i++) {
     map->add_feature (indic_features[i].tag, 1, indic_features[i].flags | F_MANUAL_ZWJ);
   }
+
+  map->add_global_bool_feature (HB_TAG('c','a','l','t'));
+  map->add_global_bool_feature (HB_TAG('c','l','i','g'));
+
   map->add_gsub_pause (clear_syllables);
 }