[stubs] Unify (and optimize) implementation of ToObject.

src/symbol.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Expects following symbols to be set in the bootstrapper during genesis:
 // - symbolHasInstance
 // - symbolIsConcatSpreadable
 // - symbolIsRegExp
 // - symbolIterator
 // - symbolToStringTag
@@ skipping 60 matching lines @@
 
 
 function SymbolKeyFor(symbol) {
   if (!IS_SYMBOL(symbol)) throw MakeTypeError(kSymbolKeyFor, symbol);
   return %SymbolRegistry().keyFor[symbol];
 }
 
 
 // ES6 19.1.2.8
 function ObjectGetOwnPropertySymbols(obj) {
-  obj = $toObject(obj);
+  obj = TO_OBJECT(obj);
 
   // TODO(arv): Proxies use a shared trap for String and Symbol keys.
 
   return ObjectGetOwnPropertyKeys(obj, PROPERTY_ATTRIBUTES_STRING);
 }
 
 //-------------------------------------------------------------------
 
 %SetCode(GlobalSymbol, SymbolConstructor);
 %FunctionSetPrototype(GlobalSymbol, new GlobalObject());
@@ skipping 25 matching lines @@
   "valueOf", SymbolValueOf
 ]);
 
 utils.InstallFunctions(GlobalObject, DONT_ENUM, [
   "getOwnPropertySymbols", ObjectGetOwnPropertySymbols
 ]);
 
 $symbolToString = SymbolToString;
 
 })