Unify symbols sharing across native scripts and runtime.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 155e9ead0870a7cb6a715eec114e3aaa4f557be7..298570abd7d52b395acd27268aa606e80d6f0efa 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -2560,9 +2560,6 @@ Handle<JSObject> Isolate::GetSymbolRegistry() {
     SetUpSubregistry(registry, map, "for");
     SetUpSubregistry(registry, map, "for_api");
     SetUpSubregistry(registry, map, "keyFor");
-    SetUpSubregistry(registry, map, "private_api");
-    heap()->AddPrivateGlobalSymbols(
-        SetUpSubregistry(registry, map, "private_intern"));
   }
   return Handle<JSObject>::cast(factory()->symbol_registry());
 }