8253516: ZGC: Remove card table functions

Reviewed-by: tschatzl, eosterlund

Author: stefank

src/hotspot/share/gc/z/zCollectedHeap.cpp

@@ -225,22 +225,6 @@ size_t ZCollectedHeap::unsafe_max_tlab_alloc(Thread* ignored) const {
   return _heap.unsafe_max_tlab_alloc();
 }
 
-bool ZCollectedHeap::can_elide_tlab_store_barriers() const {
-  return false;
-}
-
-bool ZCollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
-  // Not supported
-  ShouldNotReachHere();
-  return true;
-}
-
-bool ZCollectedHeap::card_mark_must_follow_store() const {
-  // Not supported
-  ShouldNotReachHere();
-  return false;
-}
-
 GrowableArray<GCMemoryManager*> ZCollectedHeap::memory_managers() {
   return GrowableArray<GCMemoryManager*>(1, 1, _heap.serviceability_memory_manager());
 }

src/hotspot/share/gc/z/zCollectedHeap.hpp

@@ -89,10 +89,6 @@ class ZCollectedHeap : public CollectedHeap {
   virtual size_t max_tlab_size() const;
   virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
 
-  virtual bool can_elide_tlab_store_barriers() const;
-  virtual bool can_elide_initializing_store_barrier(oop new_obj);
-  virtual bool card_mark_must_follow_store() const;
-
   virtual GrowableArray<GCMemoryManager*> memory_managers();
   virtual GrowableArray<MemoryPool*> memory_pools();