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

[Kelvin Nilsen]

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

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Commit messages:
 - Fix white space
 - Allow old-gen incrments of work between young gc
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - Merge branch 'openjdk:master' into master
 - ... and 26 more: https://git.openjdk.org/jdk/compare/b7e8952a...322e2eca

Changes: https://git.openjdk.org/jdk/pull/24810/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24810&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8355336
  Stats: 26 lines in 3 files changed: 8 ins; 14 del; 4 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