RFR: 8316182: RISC-V: SA stack walking code having trouble finding sender frame when invoking LambdaForms is involved

[Fei Yang]

On Wed, 13 Sep 2023 11:53:39 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> Hi, please consider.
> Inspired by [JDK-8313800](https://bugs.openjdk.org/browse/JDK-8313800). RISC-V also treats x8/fp as a callee-saved scratch register for some time, and it is freely used by C2-generated code. Therefore, any code in SA that uses getFP() in a compiled frame is very likely to come to grief.
> 
> Testing:
> - [x] hotspot_serviceability
> - [x] jdk_svc
> - [x] tier1

LGTM

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15714#pullrequestreview-1627074913