RFR: Merge jdk8u:master

[Andrew John Hughes]

Merge jdk8u412-b04

GHA builds will not work until [JDK-8293107](https://bugs.openjdk.org/browse/JDK-8293107) is merged in 8u462-b01

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Commit messages:
 - Merge jdk8u412-b04
 - 8168518: rcache interop with krb5-1.15
 - 8323202: [8u] Remove get_source.sh and hgforest.sh
 - 8011180: Delete obsolete scripts

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

Changes: https://git.openjdk.org/shenandoah-jdk8u/pull/69/files
  Stats: 3853 lines in 12 files changed: 261 ins; 3451 del; 141 mod
  Patch: https://git.openjdk.org/shenandoah-jdk8u/pull/69.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk8u.git pull/69/head:pull/69

PR: https://git.openjdk.org/shenandoah-jdk8u/pull/69