Implement the experimental::builtin warnings category #1219

Summary

Implement support for the Perl warnings category experimental::builtin.

Motivation

The Game::TextPacMonster 0.03 CPAN test run reaches t/01_map.t, which loads the bundled Data::Dumper. That library contains a declaration for the experimental::builtin warnings category. PerlOnJava currently aborts compilation with:

Unknown warnings category experimental::builtin

The same test also fails under the local system Perl 5.42 because the category is newer than that Perl version, while the PerlOnJava test environment identifies itself as Perl 5.44.001. This issue is therefore about providing the expected warnings-category compatibility for the PerlOnJava runtime and bundled libraries.

Desired behavior

• use warnings "experimental::builtin" is accepted when the category is available in the emulated Perl version.
• Loading bundled modules that declare or locally enable this category does not abort compilation.
• Category state follows normal warnings semantics for lexical enablement, disabling, and fatal warnings where applicable.
• Unknown genuinely unsupported warning categories continue to produce the appropriate diagnostic.

Regression context

Archived CPAN run: 20260902-105744-25704.

Game::TextPacMonster had 10 of 11 test programs pass and 433 tests pass; only t/01_map.t failed during compilation after loading Data::Dumper. The distribution itself has no native-code prerequisite relevant to this failure.

The implementation should include focused project-owned warnings coverage and rerun the affected CPAN test.