[use] Update to draft spec from Andrew Glass from August 2015

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

diff --git a/src/hb-ot-shape-complex-use.cc b/src/hb-ot-shape-complex-use.cc
index 67149ef..045ead5 100644
--- a/src/hb-ot-shape-complex-use.cc
+++ b/src/hb-ot-shape-complex-use.cc
@@ -230,8 +230,7 @@
 enum syllable_type_t {
   independent_cluster,
   virama_terminated_cluster,
-  consonant_cluster,
-  vowel_cluster,
+  standard_cluster,
   number_joiner_terminated_cluster,
   numeral_cluster,
   symbol_cluster,
@@ -322,8 +321,7 @@
 	break;
 
       case virama_terminated_cluster:
-      case consonant_cluster:
-      case vowel_cluster:
+      case standard_cluster:
       case number_joiner_terminated_cluster:
       case numeral_cluster:
       case broken_cluster:
@@ -426,15 +424,14 @@
   /* Only a few syllable types need reordering. */
   if (unlikely (!(FLAG_SAFE (syllable_type) &
 		  (FLAG (virama_terminated_cluster) |
-		   FLAG (consonant_cluster) |
-		   FLAG (vowel_cluster) |
+		   FLAG (standard_cluster) |
 		   FLAG (broken_cluster) |
 		   0))))
     return;
 
   hb_glyph_info_t *info = buffer->info;
 
-#define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB) | FLAG (USE_IV))
+#define BASE_FLAGS (FLAG (USE_B) | FLAG (USE_GB))
 
   /* Move things forward. */
   if (info[start].use_category() == USE_R && end - start > 1)