[jdk11u-dev] RFR: Merge jdk11u:master

[Christoph Langer]

Merges tag jdk-11.0.21+6 to jdk11u-dev.

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Commit messages:
 - 8314960: Add Certigna Root CA - 2
 - 8315135: Memory leak in the native implementation of Pack200.Unpacker.unpack()

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

Changes: https://git.openjdk.org/jdk11u-dev/pull/2124/files
  Stats: 633 lines in 8 files changed: 401 ins; 227 del; 5 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2124.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2124/head:pull/2124

PR: https://git.openjdk.org/jdk11u-dev/pull/2124