Function merge_consumed_exports 

pub fn merge_consumed_exports(
    name: &str,
    parsed: &[ParsedFile],
    unit_info: &BTreeMap<String, UnitInfo>,
    combined_types: &mut HashMap<String, Arc<TypeDecl>>,
    combined_methods: &mut HashMap<String, MethodTable>,
    imported_from: &mut HashMap<String, String>,
    imported_from_kind: &mut HashMap<String, UnitKind>,
    errors: &mut ErrorSink,
) -> HashMap<String, ConsumedType>

Phase 8b: merge one context’s consumes exports into the composed symbol space, recording visibility metadata in the returned consumed_types. The per-export continues (missing decl, name conflict) stay internal to the loop, which lifts out whole; name conflicts are pushed into errors and the caller’s group_error_baseline guard reacts to them after this returns.