[subset] Minor

Remove Lookup::subset().

src/hb-ot-layout-common.hh

@@ -703,17 +703,6 @@ struct Lookup
     return_trace (true);
   }
 
-  inline bool subset (hb_subset_context_t *c) const
-  {
-    TRACE_SUBSET (this);
-    struct Lookup *out = c->serializer->embed (*this);
-    if (unlikely (!out)) return_trace (false);
-    unsigned int count = subTable.len;
-    for (unsigned int i = 0; i < count; i++)
-      out->subTable[i].set (0); /* To be filled out by SubstLookup/PosLookup. */
-    return_trace (true);
-  }
-
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);

src/hb-ot-layout-gsubgpos.hh

@@ -2377,7 +2377,7 @@ struct GSUBGPOS
     if (unlikely (!out)) return_trace (false);
     out->scriptList.serialize_subset (c, this+scriptList, this);
     out->featureList.serialize_subset (c, this+featureList, this);
-    out->lookupList.serialize_subset (c, this+lookupList, this);
+    out->lookupList.set (0); /* GSUB/GPOS fill this one in. */
     if (version.to_int () >= 0x00010001u)
      out->featureVars.serialize_subset (c, this+featureVars, this);
     return_trace (true);