RFR: Merge openjdk/jdk21u:master

[William Kemper]

Merges tag jdk-21.0.7+3

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Commit messages:
 - 8338303: Linux ppc64le with toolchain clang - detection failure in early JVM startup
 - 8346880: [aix] java/lang/ProcessHandle/InfoTest.java still fails: "reported cputime less than expected"
 - 8347576: Error output in libjsound has non matching format strings
 - 8346881: [ubsan] logSelection.cpp:154:24  / logSelectionList.cpp:72:94 : runtime error: applying non-zero offset 1 to null pointer
 - 8345569: [ubsan] adjustments to filemap.cpp and virtualspace.cpp for macOS aarch64
 - 8346972: Test java/nio/channels/FileChannel/LoopingTruncate.java fails sometimes with IOException: There is not enough space on the disk
 - 8347171: (dc) java/nio/channels/DatagramChannel/InterruptibleOrNot.java fails with virtual thread factory
 - 8343882: BasicAnnoTests doesn't handle multiple annotations at the same position
 - 8347740: java/io/File/createTempFile/SpecialTempFile.java failing
 - 8302111: Serialization considerations
 - ... and 5 more: https://git.openjdk.org/shenandoah-jdk21u/compare/3e556491...b7d92cd0

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/156/files
  Stats: 1629 lines in 62 files changed: 1037 ins; 330 del; 262 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/156.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/156/head:pull/156

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/156