[serializer] do not cache resource data pointer for native source.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 51ba09dd2629db736967b47cc503fbb3eb2e67fa..68938bb5e774ef88aad1bb430ac767712df9ad90 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -224,6 +224,10 @@ class Factory final {
       const ExternalOneByteString::Resource* resource);
   MUST_USE_RESULT MaybeHandle<String> NewExternalStringFromTwoByte(
       const ExternalTwoByteString::Resource* resource);
+  // Create a new external string object for one-byte encoded native script.
+  // It does not cache the resource data pointer.
+  Handle<ExternalOneByteString> NewNativeSourceString(
+      const ExternalOneByteString::Resource* resource);
 
   // Create a symbol.
   Handle<Symbol> NewSymbol();