[serialize] FeatureVariations subset->copy

src/hb-ot-layout-common.hh

@@ -1984,10 +1984,10 @@ struct FeatureVariations
     return (this+record.substitutions).find_substitute (feature_index);
   }
 
-  bool subset (hb_subset_context_t *c) const
+  FeatureVariations* copy (hb_serialize_context_t *c) const
   {
-    TRACE_SUBSET (this);
-    return_trace (c->serializer->embed (*this));
+    TRACE_SERIALIZE (this);
+    return_trace (c->embed (*this));
   }
 
   bool sanitize (hb_sanitize_context_t *c) const

src/hb-ot-layout-gsubgpos.hh

@@ -2680,7 +2680,7 @@ struct GSUBGPOS
 			 out);
 
     if (version.to_int () >= 0x00010001u)
-     out->featureVars.serialize_subset (c, this+featureVars, out);
+     out->featureVars.serialize_copy (c->serializer, this+featureVars, out);
 
     return_trace (true);
   }