Apply a set of heuristic to improve slithIR

def apply_ir_heuristics(irs, node):
    """
        Apply a set of heuristic to improve slithIR
    """

    irs = integrate_value_gas(irs)

    irs = propagate_type_and_convert_call(irs, node)
    irs = remove_unused(irs)
    find_references_origin(irs)


    return irs