--- old/src/hotspot/share/gc/serial/serialHeap.hpp	2020-08-14 11:36:13.578258630 +0200
+++ new/src/hotspot/share/gc/serial/serialHeap.hpp	2020-08-14 11:36:13.398255335 +0200
@@ -75,10 +75,6 @@
   template <typename OopClosureType1, typename OopClosureType2>
   void oop_since_save_marks_iterate(OopClosureType1* cur,
                                     OopClosureType2* older);
-
-  // Runs the given AbstractGangTask with the current active workers.
-  // No workGang for SerialHeap, work serially with thread 0.
-  virtual void run_task(AbstractGangTask* task);
 };
 
 #endif // SHARE_GC_SERIAL_SERIALHEAP_HPP