[14u] RFR 8237632: Shenandoah: accept NULL fwdptr to cooperate with JVMTI and JFR

[Aleksey Shipilev]

On 3/2/20 4:54 PM, Zhengyu Gu wrote:
> Original bug: https://bugs.openjdk.java.net/browse/JDK-8237632

The label should be jdk14u-fix-request? Unless you want to push this into JDK 14 RC, which is the
whole other story.

> 14u Webrev: http://cr.openjdk.java.net/~zgu/JDK-8237632/14u/webrev.00/

14u backport looks good.

-- 
Thanks,
-Aleksey