RFR: 8329031: CPUID feature detection for Advanced Performance Extensions (Intel® APX)

[Jatin Bhateja]

Summary of changes include with the patch:-

1) CPUID based feature detection check for Intel APX extension (https://www.intel.com/content/www/us/en/developer/articles/technical/advanced-performance-extensions-apx.html)
2) Validation during VM initialization for extended GPRs state save / restoration by OS across context switches of java application threads executing JIT compiled code with new APX ISA.

Kindly review and share your feedback.

Best Regards,
Jatin

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Commit messages:
 - Update vm_version_x86.cpp
 - Post merge clenups.
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8329031
 - Minor modification in UseAPX flag description
 - Making UseAPX a boolean flag.
 - 32-bit build fix
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8329031
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8329031
 - 8329031: CPUID feature detection for APX during VM initialization.

Changes: https://git.openjdk.org/jdk/pull/18562/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18562&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8329031
  Stats: 179 lines in 8 files changed: 153 ins; 11 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/18562.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18562/head:pull/18562

PR: https://git.openjdk.org/jdk/pull/18562