Shenandoah: Skynet test crashed with iu + aggressive

#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/zgu/ws/jdk/src/hotspot/share/gc/shenandoah/shenandoahHeap.inline.hpp:126), pid=37776, tid=37792
# Error: Shenandoah assert_forwarded failed; Object should be forwarded

Referenced from:
  interior location: 0x0000000614a00028
  inside Java heap
    not in collection set
  region: | 4|R |BTE 614a00000, 614c00000, 614c00000|TAMS 614a00000|UWM 614c00000|U 2048K|T 2048K|G 0B|S 0B|L 2048K|CP 0

Object:
  0x000000061660bd90 - klass 0x0000000800036a38 jdk.internal.vm.StackChunk
    not allocated after mark start
    not after update watermark
    not marked strong
    not marked weak
        in collection set
  mark: mark(is_neutral no_hash age=0)
  region: | 18|CS |BTE 616600000, 616800000, 616800000|TAMS 616800000|UWM 616800000|U 2048K|T 2048K|G 0B|S 0B|L 52624B|CP 0

Forwardee:
  (the object itself)