RFR: Merge openjdk/jdk:master

[William Kemper]

Merges tag jdk-21+23

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Commit messages:
 - Merge tag 'jdk-21+23' into merge-jdk-21-23
 - 8307976: (fs) Files.createDirectories(dir) returns dir::toAbsolutePath instead of dir
 - 8308239: Tighten up accessibility of nested classes in java.lang.invoke
 - 8308246: PPC64le build broken after JDK-8304913
 - 8307326: Package jdk.internal.classfile.java.lang.constant become obsolete
 - 8306304: Fix xlc17 clang warnings in ppc and aix code
 - 8308043: Deadlock in TestCSLocker.java due to blocking GC while allocating
 - 8308185: Update Http2TestServerConnection to use SSLSocket.startHandshake()
 - 8308088: Improve class check in CollectedHeap::is_oop
 - 8296469: Instrument VMError::report with reentrant iteration step for register and stack printing
 - ... and 215 more: https://git.openjdk.org/shenandoah/compare/e48977a7...3253f2b1

The webrevs contain the adjustments done while merging with regards to each parent branch:
 - master: https://webrevs.openjdk.org/?repo=shenandoah&pr=282&range=00.0
 - openjdk/jdk:master: https://webrevs.openjdk.org/?repo=shenandoah&pr=282&range=00.1

Changes: https://git.openjdk.org/shenandoah/pull/282/files
  Stats: 122055 lines in 2096 files changed: 95833 ins; 10605 del; 15617 mod
  Patch: https://git.openjdk.org/shenandoah/pull/282.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah.git pull/282/head:pull/282

PR: https://git.openjdk.org/shenandoah/pull/282