[jdk17u-dev] RFR: 8278241: Implement JVM SpinPause on linux-aarch64

[Evgeny Astigeevich]

A backport of a configurable implementation of JVM SpinPause to improve performance of contended locks and to achieve parity with x86 which has implemented SpinPause.
The risk of changes is low. They enable one ISB-based implementation for Neoverse N1. Other AArch64 will continue using an empty implementation.
Tested for fastdebug and release builds:
- `gtest`: Passed
- `tier1`...`tier4`: Passed
- `hotspot/jtreg/runtime/Thread/TestSpinPause.java`: Passed

It can be considered as  clean. Applying the patch has an issue to find a proper position in `stubGenerator_aarch64.cpp`.  No code changes are needed after repositioning.

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Commit messages:
 - Backport bcb79fd012c9c298e58c20c59e564e9d2c16b970

Changes: https://git.openjdk.java.net/jdk17u-dev/pull/116/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u-dev&pr=116&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8278241
  Stats: 125 lines in 5 files changed: 124 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk17u-dev/pull/116.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u-dev pull/116/head:pull/116

PR: https://git.openjdk.java.net/jdk17u-dev/pull/116