[jdk21u-dev] RFR: 8316319: Generational ZGC: The SoftMaxHeapSize might be wrong when CDS decreases the MaxHeapSize

[yaqsun]

Patch can be applied cleanly. 
And test have been locally verified to pass.

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Commit messages:
 - Backport fe862639e7ce40f5adef0e482b1fb9c718e061a3

Changes: https://git.openjdk.org/jdk21u-dev/pull/126/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=126&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316319
  Stats: 40 lines in 6 files changed: 30 ins; 10 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/126.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/126/head:pull/126

PR: https://git.openjdk.org/jdk21u-dev/pull/126