[jdk21u-dev] RFR: 8330094: RISC-V: Save and restore FRM in the call stub

[Fei Yang]

On Tue, 30 Apr 2024 13:08:50 GMT, Gui Cao <gcao at openjdk.org> wrote:

> Hi, The same issue also exists in JDK21u. So I would like to backport [JDK-8330094](https://bugs.openjdk.org/browse/JDK-8330094) to jdk21u-dev. With this change, we save and restore the default floating-point control state when we enter and leave Java code, ensuring that we are still Java compatible if we're called via the JNI invocation interface with a weird FP control state. RISC-V specific change, risk is low.
> The backport is not clean because jdk21u-dev has no [JDK-8321021](https://bugs.openjdk.org/browse/JDK-8321021)
> 
> ### Testing
> 
> - [x]  Run tier1-3 tests on SOPHON SG2042 (release)

LGTM.

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Marked as reviewed by fyang (Reviewer).

PR Review: https://git.openjdk.org/jdk21u-dev/pull/545#pullrequestreview-2032922879