RFR: 8359435: AArch64: add support for 8.5 SB instruction

[Evgeny Astigeevich]

Speculation Barrier (SB) instruction can be used instead of a pair of DSB, ISB if supported. It should have better performance than DSB+ISB (https://developer.arm.com/documentation/102825/0100):

> ... a DSB+ISB sequence is expected to have a significantly greater impact on performance than an SB ...

CPUs supporting it:
- Apple M2+
- Neoverse-N2
- Neoverse-V2

Tested:
- Gtests passed

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Commit messages:
 - 8359435: AArch64: add support for 8.5 SB instruction

Changes: https://git.openjdk.org/jdk/pull/25801/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25801&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8359435
  Stats: 297 lines in 3 files changed: 5 ins; 0 del; 292 mod
  Patch: https://git.openjdk.org/jdk/pull/25801.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25801/head:pull/25801

PR: https://git.openjdk.org/jdk/pull/25801