G1: Use SoftMaxHeapSize to guide GC heuristics

*** 779,789 ****
    void pre_evacuate_collection_set(G1EvacuationInfo& evacuation_info, G1ParScanThreadStateSet* pss);
    void post_evacuate_collection_set(G1EvacuationInfo& evacuation_info,
                                      G1RedirtyCardsQueueSet* rdcqs,
                                      G1ParScanThreadStateSet* pss);
  
!   void expand_heap_after_young_collection();
    // Update object copying statistics.
    void record_obj_copy_mem_stats();
  
    // The hot card cache for remembered set insertion optimization.
    G1HotCardCache* _hot_card_cache;
--- 779,793 ----
    void pre_evacuate_collection_set(G1EvacuationInfo& evacuation_info, G1ParScanThreadStateSet* pss);
    void post_evacuate_collection_set(G1EvacuationInfo& evacuation_info,
                                      G1RedirtyCardsQueueSet* rdcqs,
                                      G1ParScanThreadStateSet* pss);
  
!   void resize_heap_after_young_collection();
!   bool expand_heap_after_young_collection();
!   void shrink_heap_after_young_collection();
!   void expand_heap_after_concurrent_mark();
! 
    // Update object copying statistics.
    void record_obj_copy_mem_stats();
  
    // The hot card cache for remembered set insertion optimization.
    G1HotCardCache* _hot_card_cache;
*** 1076,1086 ****
    inline void old_set_add(HeapRegion* hr);
    inline void old_set_remove(HeapRegion* hr);
  
    inline void archive_set_add(HeapRegion* hr);
  
!   size_t non_young_capacity_bytes() {
      return (old_regions_count() + _archive_set.length() + humongous_regions_count()) * HeapRegion::GrainBytes;
    }
  
    // Determine whether the given region is one that we are using as an
    // old GC alloc region.
--- 1080,1090 ----
    inline void old_set_add(HeapRegion* hr);
    inline void old_set_remove(HeapRegion* hr);
  
    inline void archive_set_add(HeapRegion* hr);
  
!   size_t non_young_capacity_bytes() const {
      return (old_regions_count() + _archive_set.length() + humongous_regions_count()) * HeapRegion::GrainBytes;
    }
  
    // Determine whether the given region is one that we are using as an
    // old GC alloc region.
*** 1278,1287 ****
--- 1282,1294 ----
    virtual size_t max_capacity() const;
  
    // Return the size of reserved memory. Returns different value than max_capacity() when AllocateOldGenAt is used.
    virtual size_t max_reserved_capacity() const;
  
+   // Print the soft maximum heap capacity.
+   size_t soft_max_capacity() const;
+ 
    virtual jlong millis_since_last_gc();
  
  
    // Convenience function to be used in situations where the heap type can be
    // asserted to be this type.