[jdk21u] Integrated: Merge jdk21:master

[Rob McKenna]

Merge jdk21 into jdk21u

-------------

Commit messages:
 - Merge
 - 8311923: TestIRMatching.java fails on RISC-V
 - 8308184: Launching java with large number of jars in classpath with java.protocol.handler.pkgs system property set can lead to StackOverflowError
 - 8311862: RISC-V: small improvements to shift immediate instructions
 - Merge
 - 8310873: Re-enable locked_create_entry symbol check in runtime/NMT/CheckForProperDetailStackTrace.java for RISC-V
 - 8309502: RISC-V: String.indexOf intrinsic may produce misaligned memory loads
 - Merge
 - 8310171: Bump version numbers for 21.0.1

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

Changes: https://git.openjdk.org/jdk21u/pull/14/files
  Stats: 260 lines in 11 files changed: 221 ins; 7 del; 32 mod
  Patch: https://git.openjdk.org/jdk21u/pull/14.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/14/head:pull/14

PR: https://git.openjdk.org/jdk21u/pull/14