RFR: 8345322: RISC-V: Add concurrent gtests for cmpxchg variants

[Fei Yang]

On Mon, 9 Dec 2024 16:14:13 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> So maybe: Run loops from TESTSIZE min to max, re-run this loop until we record CAS failures or something like that?

Seens to me that would be very similar with the current approach. How about we make the wrap around here explicit? Say, when the `oldvalue` reaches TESTSIZE max, we set the `newvalue` to TESTSIZE min. And we set the final expect value in `data` accordingly instead of doing a type truncation. Then we don't depend on the implementation of the compiler.

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PR Review Comment: https://git.openjdk.org/jdk/pull/22574#discussion_r1877117033