Support dynamic struct element helper args

[Th0rgal]

Summary

• add IR/Yul helpers for forwarding dynamic struct-array elements into internal helpers
• support dynamic tuple parameter member length/data/element projection in the macro
• add smoke, invariant, round-trip, and generated property-test coverage

Tests

• lake build
• lake build Contracts.Smoke
• lake build Compiler.Proofs.IRGeneration.ExprCore
• python3 scripts/check_macro_health.py

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Note

Medium Risk
Touches ABI encoding/offset calculations and macro lowering for dynamic tuple/struct parameters, which can cause subtle miscompilations if offsets/length checks are wrong; changes are localized but span compiler, validators, and proofs.

Overview
Adds new IR/Yul support for passing dynamically encoded struct/tuple values into internal helpers by introducing Expr.arrayElementDynamicDataOffset plus dynamic-member projections (Expr.paramDynamicMemberLength, Expr.paramDynamicMemberDataOffset, Expr.paramDynamicMemberElement) and compiling them to new checked Yul helpers (calldata + memory variants).

Extends validation/usage analysis/purity checks and internal helper parameter lowering to recognize these new expression forms, and updates the macro translator to lower dynamic struct-member uses in arrayLength/arrayElement, external/linked calls, and internal helper calls (including allowing struct/tuple helper params).

Adds a new smoke contract (DynamicStructElementHelperArgSmoke) and updates invariant/round-trip fuzz suites and generated Solidity property-test scaffolding; the property-test generator now falls back to an abi.decode(abi.encode(...)) placeholder for unsupported array element example values instead of failing.

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[cursor]

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

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[cursor]

Missing unconditional true for paramDynamicMemberElement usage detection

High Severity

exprUsesParamDynamicHeadWord returns exprUsesParamDynamicHeadWord innerIndex for Expr.paramDynamicMemberElement, but it needs to return true unconditionally (like paramDynamicMemberLength and paramDynamicMemberDataOffset do). The checkedParamDynamicMemberElementHelper is gated by paramDynamicHeadWordHelpersRequired, so if a function only uses paramDynamicMemberElement with a simple literal index, the helper won't be emitted and the generated Yul will reference an undefined function.

 

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[github-actions]

\n### CI Failure Hints\n\nFailed jobs: `compiler-regressions`\n\nCopy-paste local triage:\n```bash\nmake check\nlake build\nFOUNDRY_PROFILE=difftest forge test -vv\n```