These tests are currently failing with Generational Shenandoah:

$ CONF=linux-x86_64-server-fastdebug make images test TEST=runtime/cds TEST_VM_OPTS="-XX:+UseShenandoahGC -XX:ShenandoahGCMode=generational"

...because we have this condition in shenandoahHeap.cpp:

  bool can_load_archived_objects() const override { return !ShenandoahCardBarrier; }

This is a safeguard from CDS loading the archive without looking back at card tables that we need for generational GC to work. But, this load happens naturally when all objects are still young, no GC have happened yet, so no card table updates are needed.