[serializer] include global proxy in additional context snapshots.

src/snapshot/partial-serializer.h

Index: src/snapshot/partial-serializer.h
diff --git a/src/snapshot/partial-serializer.h b/src/snapshot/partial-serializer.h
index 45d64e431ef146255cbfbadedae5e1ce97802494..2d7c9ed41516e73b64f0c873f12c75476b878ee2 100644
--- a/src/snapshot/partial-serializer.h
+++ b/src/snapshot/partial-serializer.h
@@ -21,7 +21,7 @@ class PartialSerializer : public Serializer {
   ~PartialSerializer() override;
 
   // Serialize the objects reachable from a single object pointer.
-  void Serialize(Object** o);
+  void Serialize(Object** o, bool include_global_proxy);
 
  private:
   void SerializeObject(HeapObject* o, HowToCode how_to_code,