RFR: 8305351: C2 setScopedValueCache intrinsic doesn't use access API

[Martin Doerr]

On Tue, 4 Apr 2023 12:40:14 GMT, Erik Österlund <eosterlund at openjdk.org> wrote:

> The setScopedValueCache intrinsic for C2 doesn't use the access API. Instead, we store into an OopHandle with a raw store. That doesn't necessarily play well with all GCs, for example Shenandoah and generational ZGC. We should use the access API to ensure the right barriers are emitted.

This fix is for JEP 429 ([JDK-8286666](https://bugs.openjdk.org/browse/JDK-8286666)), so 17u is not affected. Only backport to JDK 20 may be desirable.

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PR Comment: https://git.openjdk.org/jdk/pull/13324#issuecomment-1511629178