RFR: 8367417: Serial: Use NMethodToOopClosure during Young GC

Thu Sep 11 13:16:12 UTC 2025

Change `MarkingNMethodClosure` to `NMethodToOopClosure` in young-gc, because no marking is done during young-gc. After that, `StrongRootsScope` becomes unnecessary as well, it's essentially calling `oops_do_marking_epilogue` to undo the effect of `MarkingNMethodClosure`.

Test: tier1-5

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Commit messages:
 - sgc-nmethod

Changes: https://git.openjdk.org/jdk/pull/27226/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27226&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367417
  Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/27226.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27226/head:pull/27226

PR: https://git.openjdk.org/jdk/pull/27226