[repacker] include LookupList size when calculating size of 16bit space for ext promotion decisions.

diff --git a/src/graph/graph.hh b/src/graph/graph.hh
index df845da..5c5b5a4 100644
--- a/src/graph/graph.hh
+++ b/src/graph/graph.hh

@@ -111,6 +111,10 @@
       return priority >= 3;
     }
 
+    size_t table_size () const {
+      return obj.tail - obj.head;
+    }
+
     int64_t modified_distance (unsigned order) const
     {
       // TODO(garretrieger): once priority is high enough, should try

diff --git a/src/graph/gsubgpos-graph.cc b/src/graph/gsubgpos-graph.cc
index 12f44f8..d12e52f 100644
--- a/src/graph/gsubgpos-graph.cc
+++ b/src/graph/gsubgpos-graph.cc

@@ -34,11 +34,14 @@
     : table_tag (table_tag_),
       graph (graph_),
       buffer (buffer_),
+      lookup_list_index (0),
       lookups ()
 {
   GSTAR* gstar = graph::GSTAR::graph_to_gstar (graph_);
-  if (gstar)
+  if (gstar) {
     gstar->find_lookups (graph, lookups);
+    lookup_list_index = gstar->get_lookup_list_index (graph_);
+  }
 
   unsigned extension_size = OT::ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>::static_size;
   buffer.alloc (num_non_ext_subtables () * extension_size);

diff --git a/src/graph/gsubgpos-graph.hh b/src/graph/gsubgpos-graph.hh
index 73abc3e..80fffaf 100644
--- a/src/graph/gsubgpos-graph.hh
+++ b/src/graph/gsubgpos-graph.hh

@@ -40,6 +40,7 @@
   hb_tag_t table_tag;
   graph_t& graph;
   hb_vector_t<char>& buffer;
+  unsigned lookup_list_index;
   hb_hashmap_t<unsigned, graph::Lookup*> lookups;
 
   HB_INTERNAL make_extension_context_t (hb_tag_t table_tag_,
@@ -224,12 +225,17 @@
     }
   }
 
+  unsigned get_lookup_list_index (graph_t& graph)
+  {
+    return graph.index_for_offset (graph.root_idx (),
+                                   get_lookup_list_field_offset());
+  }
+
   template<typename Types>
   void find_lookups (graph_t& graph,
                      hb_hashmap_t<unsigned, Lookup*>& lookups /* OUT */)
   {
-    unsigned lookup_list_idx = graph.index_for_offset (graph.root_idx (),
-                                                       get_lookup_list_field_offset());
+    unsigned lookup_list_idx = get_lookup_list_index (graph);
 
     const LookupList<Types>* lookupList =
         (const LookupList<Types>*) graph.object (lookup_list_idx).head;