[crac] RFR: 8373784: [CRaC] VM Option to require perfect CPU fit

[Radim Vansa]

Right now CRaC will refuse to restore from the image if it is not compatible with current CPU as it assumes extra features. This check can be only relaxed with -XX:+UnlockExperimentalVMOptions -XX:+IgnoreCPUFeatures.

In scenarios with -XX:CRaCIgnoreRestoreIfUnavailable it might be favorable to skip the restore and proceed with running the application from scratch with all CPU features if the image has these restricted. Therefore I propose to create a new option -XX:CheckCPUFeatures with these values:
* compatible - this is the current behaviour (default)
* exact - require CPU features from the image to match perfectly
* skip - the same behaviour as `-XX:+IgnoreCPUFeatures`.

The current `-XX:+IgnoreCPUFeatures` option will be deprecated.

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Commit messages:
 - 8373784: [CRaC] VM Option to require perfect CPU fit

Changes: https://git.openjdk.org/crac/pull/285/files
  Webrev: https://webrevs.openjdk.org/?repo=crac&pr=285&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8373784
  Stats: 146 lines in 7 files changed: 137 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/crac/pull/285.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/285/head:pull/285

PR: https://git.openjdk.org/crac/pull/285