Function collect_public_symbol_modules 

pub fn collect_public_symbol_modules(
    modules: &[(&AIRModule, &Path)],
) -> HashMap<String, String>

Build a map from every public top-level symbol name declared across modules to the dotted declared module-path that declares it (e.g. Iterable → core.iter). Covers functions, records, enums (the type name), traits, classes, effects, type aliases, and consts.

The per-module native-module path needs this for implicit imports: a §18.2-prelude trait used as an impl base (impl Iterable for Bag, with Iterable auto-imported per §18.2) is referenced without an explicit use. Emitting one file per module means the consuming main.rs must use crate::core::iter::Iterable; even though Iterable never appears in an explicit use. (Go keeps one package across files, so a same-package symbol is visible without an import; Go uses this map only to know which names are cross-module, not to emit anything.) The map lets the backend add exactly those Rust uses for names a module references but neither declares locally nor imports explicitly.

Enum variants are intentionally not recorded as separate symbols: Rust accesses a variant through its type (Ordering::Less), so importing the enum type suffices, and a synthetic Ordering_Less is not a real Rust item to use. Go (same-package) needs no imports at all.

The first declarer wins for a name declared in several modules (the dependency order modules arrives in is deterministic — see reachable_modules).