RFR: JDK-8326389: [test] improve assertEquals failure output

[Matthias Baesken]

Currently assertEquals has in the failure case sometimes confusing output like :

java.lang.RuntimeException: VM output should contain exactly one RTM locking statistics entry for method compiler.rtm.locking.TestRTMTotalCountIncrRate$Test:🔒 expected 0 to equal 1
       at jdk.test.lib.Asserts.fail(Asserts.java:634)
       at jdk.test.lib.Asserts.assertEquals(Asserts.java:205)

(I don't think we really expected that for some reason 0 equals 1)
This should be improved.

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Commit messages:
 - JDK-8326389

Changes: https://git.openjdk.org/jdk/pull/17952/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17952&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326389
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17952.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17952/head:pull/17952

PR: https://git.openjdk.org/jdk/pull/17952