Use raw extension() getter when printing a Context.

For instance, in the case of a ScriptContext,
the extension_object() getter fails.

Change-Id: Id0d65bc7c44438f60e2e824535081fa785feb3c8
Reviewed-on: https://chromium-review.googlesource.com/c/1454482Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59365}

src/objects-printer.cc

@@ -947,7 +947,7 @@ void PrintContextWithHeader(std::ostream& os, Context context,
   os << "\n - length: " << context->length();
   os << "\n - scope_info: " << Brief(context->scope_info());
   os << "\n - previous: " << Brief(context->previous());
-  os << "\n - extension_object: " << Brief(context->extension_object());
+  os << "\n - extension: " << Brief(context->extension());
   os << "\n - native_context: " << Brief(context->native_context());
   PrintFixedArrayElements(os, context);
   os << "\n";