[lilliput-jdk21u:lilliput] RFR: 8316424: [Lilliput/JDK21] ZGC/CDS-related test fixes

[Roman Kennke]

A few tests with ZGC and CDS are failing. Reason is that we disable COH with single-gen-ZGC but not with gen-ZGC, and some tests dump with one and run with the other. This causes unexpected mismatches.

Testing:
 - [x] runtime/cds/appcds/TestZGCWithCDS.java (default)
 - [x] runtime/cds/appcds/TestZGCWithCDS.java (+UCOH)
 - [x] runtime/cds/appcds/TestZGCWithCDS.java (-UCOH)
 - [x] runtime/cds/appcds/loaderConstraints/DynamicLoaderConstraintsTest.java (default)
 - [x] runtime/cds/appcds/loaderConstraints/DynamicLoaderConstraintsTest.java (+UCOH)
 - [x] runtime/cds/appcds/loaderConstraints/DynamicLoaderConstraintsTest.java (-UCOH)

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Commit messages:
 - 8316424: [Lilliput/JDK21] ZGC/CDS-related test fixes

Changes: https://git.openjdk.org/lilliput-jdk21u/pull/7/files
 Webrev: https://webrevs.openjdk.org/?repo=lilliput-jdk21u&pr=7&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316424
  Stats: 16 lines in 2 files changed: 15 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/lilliput-jdk21u/pull/7.diff
  Fetch: git fetch https://git.openjdk.org/lilliput-jdk21u.git pull/7/head:pull/7

PR: https://git.openjdk.org/lilliput-jdk21u/pull/7