RFR: 8367848: Parallel: Use NMethodToOopClosure during Young GC [v2]

[Albert Mingkun Yang]

> Replace `MarkingNMethodClosure` with `NMethodToOopClosure` during young-gc. After that, a new local `ThreadsClaimTokenScope` is introduced instead of `StrongRootsScope` to make the thread-claim-token logic visible in the current context.
>  
> Test: tier1-3

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/27336/files
  - new: https://git.openjdk.org/jdk/pull/27336/files/ec254909..69767adf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27336&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27336&range=00-01

  Stats: 18 lines in 2 files changed: 9 ins; 8 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27336.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27336/head:pull/27336

PR: https://git.openjdk.org/jdk/pull/27336