RFR (sh/jdk8): Bulk backports sh/jdk11 -> sh/jdk8

[Aleksey Shipilev]

On 2/27/20 1:27 PM, Roman Kennke wrote:
> JDK-8223184: Shenandoah: Missing roots in SRP::process_all_roots_slow

I suspect this one is not applicable to 8u. JNIHandles::weak_oops_do walks
JvmtiExport::weak_oops_do, is it not?

Similar thing caused us headache before:
  https://bugs.openjdk.java.net/browse/JDK-8223258

> Changesets:
> http://cr.openjdk.java.net/~rkennke/backport-shjdk8-2020-02-27/changesets.txt
> Webrev:
> http://cr.openjdk.java.net/~rkennke/backport-shjdk8-2020-02-27/webrev.00/

Otherwise looks good.

-- 
Thanks,
-Aleksey