[crac] RFR: 8349071: [CRaC] Disable rseq in libc on checkpoint and restore

[Timofei Pushkin]

An extended version of what was initially suggested in #31. Besides disabling rseq on checkpoint disables it on restore because it became known to also cause errors otherwise.

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Commit messages:
 - Disable rseq on restore
 - Disable rseq in libc on checkpoint

Changes: https://git.openjdk.org/crac/pull/199/files
  Webrev: https://webrevs.openjdk.org/?repo=crac&pr=199&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349071
  Stats: 55 lines in 1 file changed: 37 ins; 3 del; 15 mod
  Patch: https://git.openjdk.org/crac/pull/199.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/199/head:pull/199

PR: https://git.openjdk.org/crac/pull/199