Fix pattern matching on recursive tag union variant payloads #8842
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When extracting payload from a recursive tag union variant like Wrapper(Tree) where Tree := [..., Wrapper(Tree)], the payload is stored as a Box in memory. The extractTagValue function was incorrectly computing the payload layout from the type (which gives Tree's layout) instead of using the actual variant layout from the tag union data (which correctly shows it as a Box). This caused the bound payload value to have the wrong layout, leading to incorrect pattern matching when the payload was later matched against. The fix is to use acc.getVariantLayout(tag_index) instead of computing the layout from the type variable. This ensures we get the correct .box layout for recursive variant payloads. Fixes #8754 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Summary
Wrapper(Tree), use the actual variant layout from tag union data instead of computing from typeTest plan
test/fx/direct_recursive_tag_union.roczig build minicipassesFixes #8754
🤖 Generated with Claude Code