8275277: assert(dest_attr.is_in_cset() == (obj->forwardee() == obj)) failed: Only evac-failed objects must be in the collection set here but <addr> is not

Reviewed-by: ayang, rkennke

Author: Thomas Schatzl

src/hotspot/share/gc/g1/g1ParScanThreadState.inline.hpp

@@ -111,7 +111,7 @@ template <class T> void G1ParScanThreadState::write_ref_field_post(T* p, oop obj
   // References to the current collection set are references to objects that failed
   // evacuation. Currently these regions are always relabelled as old without
   // remembered sets, so skip them.
-  assert(dest_attr.is_in_cset() == (obj->forwardee() == obj),
+  assert(dest_attr.is_in_cset() == (obj->is_forwarded() && obj->forwardee() == obj),
          "Only evac-failed objects must be in the collection set here but " PTR_FORMAT " is not", p2i(obj));
   if (dest_attr.is_in_cset()) {
     return;