RFR: Merge openjdk/jdk21u:master

[William Kemper]

Merges tag jdk-21.0.6-ga

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Commit messages:
 - 8347010: [21u] Remove designator DEFAULT_PROMOTED_VERSION_PRE=ea for release 21.0.6
 - 8339180: Enhanced Building of Processes: Follow-on Issue
 - 8336564: Enhance mask blit functionality redux
 - 8335428: Enhanced Building of Processes
 - 8330045: Enhance array handling

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

Changes: https://git.openjdk.org/shenandoah-jdk21u/pull/152/files
  Stats: 91 lines in 4 files changed: 56 ins; 8 del; 27 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/152.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/152/head:pull/152

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/152