Fix CPAN random module compatibility gaps

[fglock]

Summary

• fix several CPAN random tester compatibility gaps across bytecode, parser diagnostics, bundled Perl shims, JSON handling, encoding, and CPAN distroprefs
• add bundled shims for Class::Load::XS and Hash::FieldHash, with a tied identity Hash::Util::FieldHash implementation for Object::ID/UNIVERSAL::AUTHORITY
• add a Pod-Parser CPAN patch so Pod::Find reports PerlOnJava core probe paths instead of jar:PERL5LIB paths
• update CPAN compatibility reports for the retested modules

Verification

• make
• timeout 1800 perl dev/tools/cpan_random_tester.pl --modules UNIVERSAL::AUTHORITY,Class::Load::XS,Pod::PlainText,XML::Directory,JSON::Any,Env::Path --timeout 900 --activity-grace 180 --max-runtime 1800 --jobs 1
• timeout 1500 perl dev/tools/cpan_random_tester.pl --modules ExtUtils::MakeMaker --timeout 1000 --activity-grace 180 --max-runtime 1500 --jobs 1
• git diff --check

Notes

• ExtUtils::MakeMaker still fails its full upstream self-test suite: 15/69 test programs, 139/1257 subtests. The original blockers seen here were fixed, but broader EUMM path/manpage/version/argument parsing compatibility remains.
• Class::Load::XS is bundled and skips normal upstream XS tests; forced bundled tests were run during development.