Function self_test 

pub fn self_test<'ir, B: BV>(
    num_threads: usize,
    arch: Vec<Def<Name, B>>,
    symtab: Symtab<'ir>,
    isa_config: &ISAConfig<B>,
    args: &[Name],
    arg_tys: &[Ty<Name>],
    ret_ty: &Ty<Name>,
    instrs1: Vec<Instr<Name, B>>,
    instrs2: Vec<Instr<Name, B>>,
) -> bool

Test that a rewritten function body is equivalent to the original body by constructing a symbolic execution problem that proves this. Note that this function should called with an uninitialized architecture.