RFR: 8333486: Parallel: Remove unused methods in psParallelCompact [v2]

[Albert Mingkun Yang]

> Trivial removing dead code.

Albert Mingkun Yang has updated the pull request incrementally with one additional commit since the last revision:

  review

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Changes:
  - all: https://git.openjdk.org/jdk/pull/19539/files
  - new: https://git.openjdk.org/jdk/pull/19539/files/56d55c6d..a3ec94dd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=19539&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=19539&range=00-01

  Stats: 9 lines in 1 file changed: 0 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/19539.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19539/head:pull/19539

PR: https://git.openjdk.org/jdk/pull/19539