[lworld] RFR: 8375602: [lworld] Test verifiers should verify the equivalence of the objects if possible

[Quan Anh Mai]

Hi,

There are numerous tests of which verifiers assert that the hash value of 2 objects are equal to verify that those objects are equal. As `acmp` has become more mature, this PR updates those to verify that 2 objects are equal. This is more straightforward and it produces a nicer debug message in case of failures.

A side effect of this PR is that it helps reproduce [JDK-8372824](https://bugs.openjdk.org/browse/JDK-8372824) in a consistent manner with `-XX:+UnlockExperimentalVMOptions -XX:PerMethodSpecTrapLimit=0 -XX:PerMethodTrapLimit=0`.

Please take a look and leave your reviews, thanks a lot.

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

Commit messages:
 - Test verifiers should check the equivalence of the objects

Changes: https://git.openjdk.org/valhalla/pull/1929/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1929&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8375602
  Stats: 324 lines in 11 files changed: 10 ins; 24 del; 290 mod
  Patch: https://git.openjdk.org/valhalla/pull/1929.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1929/head:pull/1929

PR: https://git.openjdk.org/valhalla/pull/1929