RFR: 8298701: Cleanup SA entries in ProblemList-zgc.txt.

[Chris Plummer]

The following ProblemList-zgc.txt entries need a lot of cleanup.

serviceability/sa/ClhsdbCDSCore.java                          8268722   macosx-x64
serviceability/sa/ClhsdbFindPC.java#xcomp-core                8268722,8284045   macosx-x64,generic-all
serviceability/sa/ClhsdbFindPC.java#no-xcomp-core             8268722   macosx-x64
serviceability/sa/ClhsdbFindPC.java#xcomp-process             8276402   generic-all
serviceability/sa/ClhsdbJstack.java#id0                       8276402   generic-all
serviceability/sa/ClhsdbPmap.java#core                        8268722   macosx-x64
serviceability/sa/ClhsdbPstack.java#core                      8268722   macosx-x64
serviceability/sa/TestJmapCore.java                           8268722,8268283,8270202   macosx-x64,linux-aarch64,linux-x64
serviceability/sa/TestJmapCoreMetaspace.java                  8268722,8268636   generic-all

[JDK-8268722](https://bugs.openjdk.org/browse/JDK-8268722) entries can be removed. It was closed as WNF. It doesn't really impact macosx-aarch64 (core files are reasonably small there), and on macosx-x64 all these core file tests are (probably indefinitely) problem listed for other reasons in the main problem list, so no need to problem list them here with a closed CR.

[JDK-8276402](https://bugs.openjdk.org/browse/JDK-8276402) has been closed as dup of a bug that is now fixed.

Lastly, TestJmapCore.java does fail on macosx-aarch64 due to [JDK-8268283](https://bugs.openjdk.org/browse/JDK-8268283), so its problem list entry needs to be updated to reflect that.

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

Commit messages:
 - Undo changes to TEST.groups
 - Cleanup SA entries in zgc problem list.

Changes: https://git.openjdk.org/jdk/pull/11658/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11658&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8298701
  Stats: 9 lines in 1 file changed: 0 ins; 6 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/11658.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11658/head:pull/11658

PR: https://git.openjdk.org/jdk/pull/11658