8263433: Shenandoah: Don't expect forwarded objects in set_concurrent_mark_in_progress()

Reviewed-by: shade

Author: zhengyu123

src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

@@ -1696,11 +1696,8 @@ void ShenandoahHeap::set_gc_state_mask(uint mask, bool value) {
 }
 
 void ShenandoahHeap::set_concurrent_mark_in_progress(bool in_progress) {
-  if (has_forwarded_objects()) {
-    set_gc_state_mask(MARKING | UPDATEREFS, in_progress);
-  } else {
-    set_gc_state_mask(MARKING, in_progress);
-  }
+  assert(!has_forwarded_objects(), "Not expected before/after mark phase");
+  set_gc_state_mask(MARKING, in_progress);
   ShenandoahBarrierSet::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress);
 }