8253226: Shenandoah: remove unimplemented ShenandoahStrDedupQueue::verify

Reviewed-by: rkennke, zgu

Author: shipilev

src/hotspot/share/gc/shenandoah/shenandoahStrDedupQueue.hpp

@@ -113,8 +113,6 @@ class ShenandoahStrDedupQueue : public StringDedupQueue {
   bool pop_candidate(oop& obj);
 
   void set_producer_buffer(ShenandoahQueueBuffer* buf, size_t queue_id);
-
-  void verify(ShenandoahQueueBuffer* head);
 };
 
 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHSTRDEDUPQUEUE_HPP