RFR: 8286829: Shenandoah: fix Shenandoah Loom support [v3]

[Zhengyu Gu]

On Wed, 1 Jun 2022 10:10:13 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> src/hotspot/share/gc/shenandoah/shenandoahMark.inline.hpp line 73:
>> 
>>> 71:     if (obj->is_instance()) {
>>> 72:       // Case 1: Normal oop, process as usual.
>>> 73:       if (ContinuationGCSupport::relativize_stack_chunk(obj)) {
>> 
>> Ooof, this is very hot code path. Is there any way to do this without injecting the code here?
>
> Um, this conversation seems to be "resolved" without the answer.

Hmm... somehow, my comments gone missing.

Yes, I am award of it, but could not find a better place, any suggestions are welcome.

ZGC takes the similar hit [here](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/gc/z/zMark.cpp#L289).

Let's get this in for correctness and work on optimizing it in followup CR.

Thanks.

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PR: https://git.openjdk.java.net/jdk/pull/8924