RFR: 8277654: Shenandoah: Don't produce new memory state in C2 LRB runtime call [v2]

[Aleksey Shipilev]

On Fri, 26 Nov 2021 09:42:34 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> The runtime call in expanded Shenandoah LRB doesn't need to produce (and consume) raw memory state. I believe this is a left-over from when the LRB (or WB) allocated from TLABs, and would mess with TLAB pointers, when not ordered correctly. (Also, we used to require ordering with RBs back when we had them, but we already removed that memory dependency on -8 offset)
>> 
>> Testing:
>>  - [x] hotspot_gc_shenandoah
>>  - [x] specjvm -XX:+UseShenandoahGC
>>  - [x] tier1
>>  - [x] tier2
>>  - [x] tier3
>
> Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove verify_raw_mem()

Looks okay. Does it affect performance in any way?

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Marked as reviewed by shade (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/6526