[runtime] Migrate Object.getOwnPropertySymbols to C++.

src/js/symbol.js

Index: src/js/symbol.js
diff --git a/src/js/symbol.js b/src/js/symbol.js
index 5be6e0168d7a2d2629340264fdfcf09b3db0de3b..a5d80a61801b6afe3b607b4db189299cdfe6e933 100644
--- a/src/js/symbol.js
+++ b/src/js/symbol.js
@@ -11,7 +11,6 @@
 // -------------------------------------------------------------------
 // Imports
 
-var GlobalObject = global.Object;
 var GlobalSymbol = global.Symbol;
 var hasInstanceSymbol = utils.ImportNow("has_instance_symbol");
 var isConcatSpreadableSymbol =
@@ -73,18 +72,8 @@ function SymbolKeyFor(symbol) {
   return %SymbolRegistry().keyFor[symbol];
 }
 
-
-// ES6 19.1.2.8
-function ObjectGetOwnPropertySymbols(obj) {
-  obj = TO_OBJECT(obj);
-
-  return %GetOwnPropertyKeys(obj, PROPERTY_FILTER_SKIP_STRINGS);
-}
-
 // -------------------------------------------------------------------
 
-%FunctionSetPrototype(GlobalSymbol, new GlobalObject());
-
 utils.InstallConstants(GlobalSymbol, [
   // TODO(rossberg): expose when implemented.
   // "hasInstance", hasInstanceSymbol,
@@ -108,8 +97,6 @@ utils.InstallFunctions(GlobalSymbol, DONT_ENUM, [
 ]);
 
 %AddNamedProperty(
-    GlobalSymbol.prototype, "constructor", GlobalSymbol, DONT_ENUM);
-%AddNamedProperty(
     GlobalSymbol.prototype, toStringTagSymbol, "Symbol", DONT_ENUM | READ_ONLY);
 
 utils.InstallFunctions(GlobalSymbol.prototype, DONT_ENUM | READ_ONLY, [
@@ -121,10 +108,6 @@ utils.InstallFunctions(GlobalSymbol.prototype, DONT_ENUM, [
   "valueOf", SymbolValueOf
 ]);
 
-utils.InstallFunctions(GlobalObject, DONT_ENUM, [
-  "getOwnPropertySymbols", ObjectGetOwnPropertySymbols
-]);
-
 // -------------------------------------------------------------------
 // Exports