8162929: Enqueuing dirty cards into a single DCQS during GC does not scale

Refactor into G1RedirtyCardsQueue[Set] and G1DirtyCardQueueSet

Reviewed-by: tschatzl, sangheki

src/hotspot/share/gc/shared/ptrQueue.hpp

@@ -296,6 +296,10 @@ public:
 class PtrQueueSet {
   BufferNode::Allocator* _allocator;
 
+  // Noncopyable - not defined.
+  PtrQueueSet(const PtrQueueSet&);
+  PtrQueueSet& operator=(const PtrQueueSet&);
+
 protected:
   bool _all_active;
 
@@ -309,6 +313,9 @@ protected:
 
 public:
 
+  // Return the associated BufferNode allocator.
+  BufferNode::Allocator* allocator() const { return _allocator; }
+
   // Return the buffer for a BufferNode of size buffer_size().
   void** allocate_buffer();