Fix fallout from 975bdd5ef562e37655067b703b2b9ca7481f4985

Ouch!
diff --git a/src/hb-ot-map.cc b/src/hb-ot-map.cc
index 504f094..46bf2db 100644
--- a/src/hb-ot-map.cc
+++ b/src/hb-ot-map.cc
@@ -43,6 +43,10 @@
 {
   memset (this, 0, sizeof (*this));
 
+  feature_infos.init ();
+  for (unsigned int table_index = 0; table_index < 2; table_index++)
+    stages[table_index].init ();
+
   face = face_;
   props = *props_;
 
@@ -63,6 +67,13 @@
   }
 }
 
+hb_ot_map_builder_t::~hb_ot_map_builder_t (void)
+{
+  feature_infos.fini ();
+  for (unsigned int table_index = 0; table_index < 2; table_index++)
+    stages[table_index].fini ();
+}
+
 void hb_ot_map_builder_t::add_feature (hb_tag_t tag, unsigned int value,
 				       hb_ot_map_feature_flags_t flags)
 {