perf: reduce reference-counting overhead and DBIx::Class warnings

[fglock]

Summary

• register tracked scalar owners once after DESTROY-rescue handling instead of twice
• remove redundant synchronized wrappers from the explicitly single-threaded scalar registry
• remove empty reverse weak-reference buckets during unweaken
• stop caught optional base::import failures from printing duplicate stderr diagnostics
• align bundled DynaLoader and bytes file versions with their Java runtime versions
• patch Exception::Class 1.45 generated subclasses to match the source file registered in %INC
• add focused performance and version-consistency regression coverage

Performance

Three fresh JVM runs of dev/bench/benchmark_refcount_store.pl:

Revision	Median CPU time
master (168466619)	2.71 s
this branch	2.41 s

This is an 11.1% reduction in CPU time for tracked reference stores after weaken() activates lifecycle bookkeeping.

The ordinary method benchmark remained approximately 2.35 CPU seconds on both revisions.

DBIx::Class warnings

t/00describe_environment.t no longer reports:

• empty Getopt::Long::Descriptive base packages from caught optional-dependency probes
• Params::ValidationCompiler generated exception version mismatches
• DynaLoader or bytes runtime/file version mismatches

Exception::Class 1.45 still contains the upstream 1.1/1.45 mismatch; the CPAN distroprefs patch keeps the generated class version consistent with Exception/Class.pm while preserving its %INC registration.

Validation

• standard Perl: prove src/test/resources/unit/core_module_file_versions.t
• PerlOnJava: ./jperl src/test/resources/unit/core_module_file_versions.t
• Exception::Class 1.45: 7 files, 86 tests, all successful
• DBIx::Class t/00describe_environment.t: passed with none of the targeted warnings
• make: successful
• ./jcpan --jobs 8 -t DBIx::Class
  • 314 files
  • 13,121 tests
  • 818 seconds wall time
  • all tests successful

Safety notes

Two broader reference-counting optimizations were evaluated and rejected after unit-test regressions:

• conditionally skipping temporary reachability roots
• resetting the global weak-reference mode after the last weak reference cleared

The retained performance changes preserve the existing lifecycle state machine. The warning changes retain catchable base exceptions and validate file/runtime version consistency with a portable test that also passes on standard Perl.

Generated with Codex