[riscv-port-jdk11u:riscv-port] RFR: 8316645: RISC-V: Remove dependency on libatomic by adding cmpxchg 1b

[Ludovic Henry]

On Thu, 7 Mar 2024 12:12:05 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> For CI builds it helps to remove this.
> [8317335](https://bugs.openjdk.org/browse/JDK-8317335) is not needed as there is no gtest for atomic in 11.

Marked as reviewed by luhenry (no project role).

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PR Review: https://git.openjdk.org/riscv-port-jdk11u/pull/10#pullrequestreview-1923224274