[jdk25u-dev] RFR: 8342659: Test vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects002/referringObjects002.java failed: Class nsk.share.jdi.TestClass1 was not unloaded

[SendaoYan]

Hi all,

This pull request contains a backport of commit [e62a7fa3](https://github.com/openjdk/jdk/commit/e62a7fa3832bbba11e6d630015f85ae945fac824) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.

This is test bug fix which make test more robustness. Change has been verified locally on linux-x64 by run test vmTestbase/nsk/jdi/ObjectReference/referringObjects/referringObjects002/referringObjects002.java. This backport also will make 
JDK-8375485 backported cleanly.

Thanks!

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

Commit messages:
 - Backport e62a7fa3832bbba11e6d630015f85ae945fac824

Changes: https://git.openjdk.org/jdk25u-dev/pull/198/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=198&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342659
  Stats: 54 lines in 2 files changed: 8 ins; 37 del; 9 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/198.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/198/head:pull/198

PR: https://git.openjdk.org/jdk25u-dev/pull/198