Function extract_final_equalities 

pub(crate) fn extract_final_equalities<R: RcUpdater>(
    equalities: &[Equality],
    body: &Source<'_>,
    explicit_symbols: &ExplicitSymbolTable,
    implicit_symbols: &mut ImplicitSymbolTable,
    memory_map: &MemoryMap,
    index_register_assigner: &mut IndexRegisterAssigner,
    rc_allocator: &mut R,
    final_symbols: &mut FinalSymbolTable,
    bad_symbol_definitions: &mut BTreeMap<SymbolName, ProgramError>,
) -> Result<(), AssemblerFailure>

Determine the numerical value of all equalities, where they have one.

We do this in order to identify problems with symbol definitons and to generate information that we may need to emit into the ouptut listing.

This function isn’t actually needed to generate the output binary.