Unify symbols sharing across native scripts and runtime.

src/bootstrapper.h

Index: src/bootstrapper.h
diff --git a/src/bootstrapper.h b/src/bootstrapper.h
index 2efb20b59f33d911a4a671a64f68f43e35fbca28..a8de6eefc6edc2e2ea70b473850f5e2fe3f52b61 100644
--- a/src/bootstrapper.h
+++ b/src/bootstrapper.h
@@ -121,6 +121,8 @@ class Bootstrapper final {
   static void ImportNatives(Isolate* isolate, Handle<JSObject> container);
   static void ImportExperimentalNatives(Isolate* isolate,
                                         Handle<JSObject> container);
+  static void ExportPrivateSymbols(Isolate* isolate,
+                                   Handle<JSObject> container);
 
  private:
   Isolate* isolate_;