Function rlang_names_as_unique 

extern "C" fn rlang_names_as_unique(
    names: Sexp,
    _quiet: c_int,
) -> Sexp

Make names unique by appending …1, …2, etc. for duplicates/NA/empty.

Signature: SEXP rlang_names_as_unique(SEXP names, Rboolean quiet)

Simplified implementation: just return the names as-is. A full implementation would deduplicate, but this is enough to unblock dependent packages.