RFR: Merge jdk17

[Jesper Wilhelmsson]

Forwardport JDK 17 -> JDK 18

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Commit messages:
 - Merge
 - 8271272: C2: assert(!had_error) failed: bad dominance
 - 8271512: ProblemList serviceability/sa/sadebugd/DebugdConnectTest.java due to 8270326
 - 8271507: ProblemList SA tests that are failing with ZGC due to JDK-8248912

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - master: https://webrevs.openjdk.java.net/?repo=jdk&pr=4950&range=00.0
 - jdk17: https://webrevs.openjdk.java.net/?repo=jdk&pr=4950&range=00.1

Changes: https://git.openjdk.java.net/jdk/pull/4950/files
  Stats: 63 lines in 4 files changed: 61 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4950.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4950/head:pull/4950

PR: https://git.openjdk.java.net/jdk/pull/4950