jmx-dev RFR: 8274398: Suppress more warnings on non-serializable non-transient instance fields in management libs

[Joe Darcy]

Follow-up change to JDK-8232442, augmentations to javac's Xlint:serial checking are out for review (#5709) and various management libraries would need some changes to pass under the expanded checks.

The changes are to suppress warnings where non-transient fields in serializable types are not declared with a type statically known to be serializable. That isn't necessarily a correctness issues, but it does merit further scrutiny.

I'll run a script to update copyright years before a push.

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Commit messages:
 - 8274398: Suppress more warnings on non-serializable non-transient instance fields in management libs

Changes: https://git.openjdk.java.net/jdk/pull/5726/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5726&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274398
  Stats: 12 lines in 8 files changed: 12 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5726.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5726/head:pull/5726

PR: https://git.openjdk.java.net/jdk/pull/5726