Function package_module_symbol 

pub fn package_module_symbol(
    package: &str,
    module: &str,
    symbol: &str,
) -> MangledName

Internal module symbol for a declaration in a multi-file package. module is the canonicalized package-relative path (util, internal/math) — no leading ./, no .subm suffix. Root-exported (public) symbols use package_symbol instead.