[jdk17u-dev] RFR: 8186670: Implement _onSpinWait() intrinsic for AArch64

[Evgeny Astigeevich]

Tested with fastdebug build:
- `make test TEST="gtest"`: Passed
- `make run-test TEST="tier1"`: Passed
- `make run-test TEST="tier2"`: Passed
- `make run-test TEST=hotspot/jtreg/compiler/onSpinWait`: Passed

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Commit messages:
 - Backport 6954b98f8faf29b6c2d13687a7a94e83302bdd85

Changes: https://git.openjdk.java.net/jdk17u-dev/pull/88/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u-dev&pr=88&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8186670
  Stats: 766 lines in 13 files changed: 764 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk17u-dev/pull/88.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u-dev pull/88/head:pull/88

PR: https://git.openjdk.java.net/jdk17u-dev/pull/88