RFR: 8305236: The LoadLoad barrier has been useless after JDK-8220051

[SUN Guoyun]

After JDK-8220051, Interpreter::notice_safepoints() only be executed at a safe point, so LoadLoad barrier is useless.
Barrier directives are generally time-consuming, so this patch removes LoadLoad be used for aarch64 and riscv.

Please help review it.

Thanks.

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Commit messages:
 - 8305236: The LoadLoad barrier has been useless after JDK-8220051

Changes: https://git.openjdk.org/jdk/pull/13244/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13244&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305236
  Stats: 24 lines in 2 files changed: 0 ins; 24 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13244.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13244/head:pull/13244

PR: https://git.openjdk.org/jdk/pull/13244