RFR(XXS) 8223184: Shenandoah: Missing roots in SRP::process_all_roots_slow

[Zhengyu Gu]

Added missing roots in SRP::process_all_root_slow().

Bug: https://bugs.openjdk.java.net/browse/JDK-8223184
Webrev: http://cr.openjdk.java.net/~zgu/JDK-8223184/webrev.00/

Test:
   hotspot_gc_shenandoah with -XX:+ShenandoahVerify (fastdebug and release)

Thanks,

-Zhengyu