RFR: 8355336: GenShen: Resume Old GC even with back-to-back Young GC triggers [v2]

[Kelvin Nilsen]

> Allow old-gen concurrent marking cycles to get their full time slice even when young-gc is triggered back-to-back.

Kelvin Nilsen has updated the pull request incrementally with one additional commit since the last revision:

  Fix indentation

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24810/files
  - new: https://git.openjdk.org/jdk/pull/24810/files/322e2eca..eaeb4efc

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24810&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24810&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24810.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24810/head:pull/24810

PR: https://git.openjdk.org/jdk/pull/24810