Function assemble_pass3 

fn assemble_pass3(
    directive: Directive,
    explicit_symtab: &mut ExplicitSymbolTable,
    implicit_symtab: &mut ImplicitSymbolTable,
    memory_map: &mut MemoryMap,
    index_register_assigner: &mut IndexRegisterAssigner,
    body: &Source<'_>,
    listing: &mut Listing,
) -> Result<(Binary, FinalSymbolTable), AssemblerFailure>

Pass 3 generates binary code.