[jdk20] RFR: 8298888: ProblemList gc/g1/TestVerifyGCType.java on linux and macosx

[Daniel D. Daugherty]

A batch of trivial fixes to ProblemList tests:

[JDK-8298888](https://bugs.openjdk.org/browse/JDK-8298888) ProblemList gc/g1/TestVerifyGCType.java on linux and macosx
[JDK-8298889](https://bugs.openjdk.org/browse/JDK-8298889) ProblemList runtime/StackGuardPages/TestStackGuardPages.java on linux
[JDK-8298891](https://bugs.openjdk.org/browse/JDK-8298891) ProblemList vmTestbase/nsk/monitoring/MemoryPoolMBean/isCollectionUsageThresholdExceeded/isexceeded002/TestDescription.java with ZGC
[JDK-8298892](https://bugs.openjdk.org/browse/JDK-8298892)
ProblemList vmTestbase/nsk/sysdict/vm/stress/chain/chain008/chain008.java with ZGC

-------------

Commit messages:
 - 8298892: ProblemList vmTestbase/nsk/sysdict/vm/stress/chain/chain008/chain008.java with ZGC
 - 8298891: ProblemList vmTestbase/nsk/monitoring/MemoryPoolMBean/isCollectionUsageThresholdExceeded/isexceeded002/TestDescription.java with ZGC
 - 8298889: ProblemList runtime/StackGuardPages/TestStackGuardPages.java on linux
 - 8298888: ProblemList gc/g1/TestVerifyGCType.java on linux and macosx

Changes: https://git.openjdk.org/jdk20/pull/42/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20&pr=42&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298888
  Stats: 4 lines in 2 files changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk20/pull/42.diff
  Fetch: git fetch https://git.openjdk.org/jdk20 pull/42/head:pull/42

PR: https://git.openjdk.org/jdk20/pull/42