8236073: G1: Use SoftMaxHeapSize to guide GC heuristics

*** 28,37 ****
--- 28,39 ----
  #include "gc/g1/g1BarrierSet.hpp"
  #include "gc/g1/g1CollectedHeap.inline.hpp"
  #include "gc/g1/g1CollectorState.hpp"
  #include "gc/g1/g1ConcurrentMark.inline.hpp"
  #include "gc/g1/g1ConcurrentMarkThread.inline.hpp"
+ #include "gc/g1/g1ConcurrentHeapResize.hpp"
+ #include "gc/g1/g1ConcurrentHeapResizeThread.hpp"
  #include "gc/g1/g1DirtyCardQueue.hpp"
  #include "gc/g1/g1HeapVerifier.hpp"
  #include "gc/g1/g1OopClosures.inline.hpp"
  #include "gc/g1/g1Policy.hpp"
  #include "gc/g1/g1RegionMarkStatsCache.inline.hpp"
*** 1207,1217 ****
      if (ClassUnloadingWithConcurrentMark) {
        GCTraceTime(Debug, gc, phases) debug("Purge Metaspace", _gc_timer_cm);
        ClassLoaderDataGraph::purge();
      }
  
!     _g1h->resize_heap_if_necessary();
  
      compute_new_sizes();
  
      verify_during_pause(G1HeapVerifier::G1VerifyRemark, VerifyOption_G1UsePrevMarking, "Remark after");
  
--- 1209,1222 ----
      if (ClassUnloadingWithConcurrentMark) {
        GCTraceTime(Debug, gc, phases) debug("Purge Metaspace", _gc_timer_cm);
        ClassLoaderDataGraph::purge();
      }
  
!     // Don't resize heap in remark if concurrent resizing is in progress
!     if (!_g1h->concurrent_heap_resize()->resize_thread()->during_cycle()) {
!       _g1h->resize_heap_if_necessary(true);
!     }
  
      compute_new_sizes();
  
      verify_during_pause(G1HeapVerifier::G1VerifyRemark, VerifyOption_G1UsePrevMarking, "Remark after");