fix: correct record equals/toString/hashCode for reference and array components (#628)

[Darshan-dev57]

Fix #628
Three bugs fixed in executeRecord() on call-site-generation branch:

1. equals() for array components: was doing deep element comparison, now uses reference identity (JEP 395: Objects.equals() on arrays delegates to Object.equals() = reference identity).

2. toString() for String/boxed/reference components: was printing JPF heap addresses (e.g. java.lang.String@209). Now:

   • String: ei.asString() for actual content
   • Boxed JDK types: wrapped value via 'value' field
   • Arrays: [I@hexHash format (Object.toString() semantics)
   • Other references: ClassName@hexHash

3. equals() for boxed types (Integer, Long, etc.): was using reference identity, now compares by wrapped value using a safe whitelist of known JDK boxed types. User classes with a 'value' field but identity-based equals() are NOT affected.

4. hashCode() made consistent with Java record semantics:

   • String: content hash
   • Boxed JDK types: wrapped value hash
   • Arrays: content-based hash, recursively handling multidimensional arrays
   • Nested records: recursive hash
   • Other references: identity-based hash

Added RecordReferenceComponentTest regression coverage for arrays, strings, boxed types, identity classes, null components, nested records, different-length arrays, and multidimensional arrays.

Verified: all 17 regression tests pass and the full build succeeds.

[cyrille-artho]

Good work! Tests: Please check whether higher dimensions in arrays (as well as their content) are properly hashed.

[cyrille-artho]

With the new tests, there are two possible outcomes: (1) they do not all pass, in which case please look at the hash values and how to fix them; (2) they pass, in which case please update the PR.

[cyrille-artho]

Please update the tests as in the previous comment.

[Darshan-dev57]

Updated as requested. Added tests for different-length arrays and multidimensional arrays, including equivalent multidimensional arrays. The array hash implementation now recursively hashes array contents. All 17 RecordReferenceComponentTest tests pass, and the full build succeeds.

[cyrille-artho]

Hi,
Thank you for the update. I have now 12 unit tests failing on Mac OS with Java 17.0.20.
With Java 17.0.9 on Mac OS (graalvm), I have 14 unit tests failing.
On Ubuntu 24.04.02 (Darshan's system), all unit tests pass.