RFR: 8326603: Test com/sun/jdi/EATests.java#id0 performs synchronization on a value based class

[Alex Menkov]

The fix updates the test to not synchronize on `Integer`, and use `Object` instead

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Commit messages:
 - fix

Changes: https://git.openjdk.org/jdk/pull/29679/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29679&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326603
  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29679.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29679/head:pull/29679

PR: https://git.openjdk.org/jdk/pull/29679