RFR: 8374449: Shenandoah: Leaf locks used by Shenandoah need lower ranks [v2]

[William Kemper]

> Reduce the rank of `safepoint` locks and rename them to avoid confusion with `nosafepoint` ranked locks.

William Kemper has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:

 - Merge remote-tracking branch 'jdk/master' into lower-controller-lock-ranks
 - Add constant for control lock rank
 - More lock rank tweaks
 - Go even lower, don't check for safepoint when taking the locks
 - Merge remote-tracking branch 'jdk/master' into lower-controller-lock-ranks
 - Use an even lower rank
 - Lower controller lock ranks to avoid false deadlock detection

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Changes:
  - all: https://git.openjdk.org/jdk/pull/29333/files
  - new: https://git.openjdk.org/jdk/pull/29333/files/e3086a85..e8f32655

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29333&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29333&range=00-01

  Stats: 26446 lines in 791 files changed: 12573 ins; 4503 del; 9370 mod
  Patch: https://git.openjdk.org/jdk/pull/29333.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29333/head:pull/29333

PR: https://git.openjdk.org/jdk/pull/29333