(module loop_str_recur_literal_no_leak_pin
  ; mir.4 (#49 soundness, recur-arg leg): a Str loop binder whose
  ; `recur` rebinds it to a fresh static LITERAL each iteration. Without
  ; recur-arg Heap promotion the literal "reset" would be stored static
  ; into the binder alloca and dec'd on the next supersede — UB on a
  ; header-less static. lower_to_mir flips both the seed "x" and the
  ; recur literal "reset" to StrRep::Heap, so codegen str_clones each
  ; into an owned heap slab; every supersede dec then frees a real slab.
  ; Trace: seed slab1("x"); recur0 slab2("reset") decs slab1; recur1
  ; slab3 decs slab2; recur2 slab4 decs slab3; exit acc=slab4, print
  ; consumes/frees it. allocs=4 frees=4 live=0. Expected stdout: reset.
  (fn main (type (fn-type (params) (ret (own (con Unit))) (effects IO))) (params)
    (body
      (let s
        (loop (acc (con Str) "x") (i (con Int) 0)
          (if (app ge i 3)
              acc
              (recur "reset" (app + i 1))))
        (app print s)))))