[andrewtdiz]

Summary

• detect module-level assignments to function declaration names before lowering
• materialize only those function declarations as mutable local slots initialized to the original function reference
• add an exact Node parity fixture for Issue Two ES5 correctness bugs: Object(null)→{} and function-declaration reassignment #3149 Bug 2 covering call, alias, and constructor behavior

Scope

This addresses Issue #3149 Bug 2: reassigned function-declaration bindings. The Object(null)/Object() call-form behavior is handled separately in PR #3343.

Verification

• Baseline exact fixture failed before the fix: Perry kept calling the original function declaration after reassignment
• ./run_parity_tests.sh --suite node-suite --filter node-suite/globals/function-decl-reassign
• ./run_parity_tests.sh --suite node-suite --filter node-suite/globals/global-functions
• cargo check -p perry-hir
• cargo check -p perry-hir -p perry
• cargo fmt --all -- --check
• ./scripts/check_file_size.sh
• jq empty test-parity/known_failures.json
• git diff --check origin/main...HEAD && git diff --check