RFR: 8351651: Cleanup LockStack::is_owning_thread [v3]

[Coleen Phillimore]

> This is a minor mostly trivial change I found while reading through code looking for something else.
> Tested with tier1-4.

Coleen Phillimore has updated the pull request incrementally with one additional commit since the last revision:

  Fixed cast, compiled out is_owning_thread.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23981/files
  - new: https://git.openjdk.org/jdk/pull/23981/files/0c9d4768..18ddb3b1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23981&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23981&range=01-02

  Stats: 4 lines in 2 files changed: 0 ins; 1 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23981.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23981/head:pull/23981

PR: https://git.openjdk.org/jdk/pull/23981