TASK-214337 debug code

[balupillai]

Note

Medium Risk
Touches core GC heap list manipulation and adds frequent validation/abort paths, which could impact performance or change failure modes (hard abort) if invariants are violated.

Overview
Adds debug-only style heap integrity checks around GC heap TAILQ operations to catch corruption early. A new validate_heap_objects() walk and targeted post-TAILQ_INSERT_HEAD backlink checks verify object pointers, tt range, owner, and tqe_prev/tqe_next linkage, aborting via tailq_abort() with detailed logging.

Runs these validations at key points in new_obj, luaC_inherit_thread (before/after transfer), local_collection (entry, after marking, before/after reclaim, after finalization/free), and trace_heap, and reorders finalize_deferred() to run before unblocking the collector to keep heap invariants checked during finalization.

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[Copilot]

Pull request overview

Adds new heap integrity validation to detect GC heap corruption and abort early, integrated into key GC lifecycle points and global tracing to surface memory/list corruption issues closer to their source.

Changes:

• Introduces validate_heap_objects(lua_State *L, const char *where) to walk L->heap->objects and validate node pointers/type/ownership, aborting on failure.
• Calls this validation before/after heap transfer in luaC_inherit_thread() and at multiple stages of local_collection().
• Adds basic corruption checks inside trace_heap() during global tracing.

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[cursor]

✅ Bugbot reviewed your changes and found no new issues!

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 4 comments.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 6 comments.

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