ES6: Implement WeakSet

src/objects-visiting.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 92 matching lines @@
                                  JSSet::kSize);
 
     case JS_MAP_TYPE:
       return GetVisitorIdForSize(kVisitStruct,
                                  kVisitStructGeneric,
                                  JSMap::kSize);
 
     case JS_WEAK_MAP_TYPE:
       return kVisitJSWeakMap;
 
+    case JS_WEAK_SET_TYPE:
+      return kVisitJSWeakSet;
+
     case JS_REGEXP_TYPE:
       return kVisitJSRegExp;
 
     case SHARED_FUNCTION_INFO_TYPE:
       return kVisitSharedFunctionInfo;
 
     case JS_PROXY_TYPE:
       return GetVisitorIdForSize(kVisitStruct,
                                  kVisitStructGeneric,
                                  JSProxy::kSize);
@@ skipping 67 matching lines @@
                                      kVisitStructGeneric,
                                      instance_size);
 
     default:
       UNREACHABLE();
       return kVisitorIdCount;
   }
 }
 
 } }  // namespace v8::internal