void VM_G1CollectFull::doit() {

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      G1CollectedHeap* g1h = G1CollectedHeap::heap();
      GCCauseSetter x(g1h, _gc_cause);

  {- -------------------------------------------
  (1) G1CollectedHeap::do_full_collection() を呼び出すだけ.
      ---------------------------------------- -}

      g1h->do_full_collection(false /* clear_all_soft_refs */);
    }