GeezerVison

Summary

Extract the independent bytecode-tooling changes from #8954.

• Decode Python 3.15 IMPORT_NAME name indices and lazy/eager flags in the disassembly fallback, while preserving pre-3.15 indexing.
• Reject opcode IDs that disagree with CPython or place RustPython-only instructions in occupied slots.
• Restrict deoptimization families to the current opcode enum and avoid self/duplicate entries.
• Reuse one CPython source analysis during a generator invocation.

This changes three tooling files only. It does not change the parser, interpreter, canonical libraries, generated metadata, or test fixtures. Unused metadata-override extensions from the integration branch are not included.

Validation

Against CPython 3.15.0 d220409a13b77de7a6c30abe16ea90db01528edc:

• Normal commit hooks pass.
• Both existing metadata generators, with outputs redirected outside the checkout, reproduce the tracked Rust and Python metadata byte-for-byte. One source analysis served 354 cache hits.
• All 245 canonical opcode IDs match; the only RustPython-only entry, BuildListFromArg = 219, occupies an upstream-free slot. Controlled metadata-only invalid-ID checks reject both a wrong canonical ID and an occupied custom slot.
• Direct disassembly-fallback comparisons match CPython 3.15 for nine ordinary, one lazy, and one eager import from existing source files. All nine pre-3.15 imports also match CPython 3.13. Both versions pass the existing disassembly CLI smoke check. Input fixtures are compiled/disassembled, not executed.

The unmodified baseline generator exceeded a bounded 90-second check without producing output; it is not reported as a pass or used for a timing claim. Workspace/C-API runtime suites were not run for this tooling-only change. Hosted CI is pending.

AI assistance: OpenAI Codex extracted, reviewed, and validated these changes under maintainer direction. Model version unavailable.