[riscv-port-jdk17u:riscv-port] RFR: 8308089: (riscv-port-jdk17u) Intrinsify Unsafe.storeStoreFence

[Xiaolin Zheng]

[JDK-8252990](https://bugs.openjdk.org/browse/JDK-8252990) was recently ported to jdk17u in April. We should also enable the matching rule for `StoreStoreFence` on the WIP riscv-port-jdk17u repo.

Found the small fastdebug crash when backporting #51 using `-Xcomp`.

Testing a hotspot tier1~2 in progress.

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Commit messages:
 - Missing: RISC-V: JDK-8252990: Intrinsify Unsafe.storeStoreFence

Changes: https://git.openjdk.org/riscv-port-jdk17u/pull/52/files
 Webrev: https://webrevs.openjdk.org/?repo=riscv-port-jdk17u&pr=52&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8308089
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/riscv-port-jdk17u/pull/52.diff
  Fetch: git fetch https://git.openjdk.org/riscv-port-jdk17u.git pull/52/head:pull/52

PR: https://git.openjdk.org/riscv-port-jdk17u/pull/52