ocaml: phase 5.1 ackermann.ml baseline (ack(3, 4) = 125)

Classic Ackermann function:

  let rec ack m n =
    if m = 0 then n + 1
    else if n = 0 then ack (m - 1) 1
    else ack (m - 1) (ack m (n - 1))

ack(3, 4) = 125, expanding to ~6700 evaluator frames — a useful
stress test of the call stack and control transfer. Real OCaml
evaluates this in milliseconds; ours takes ~2 minutes on a
contended host but completes correctly.

40 baseline programs total.

lib/ocaml/baseline/ackermann.ml

@@ -0,0 +1,8 @@
+let rec ack m n =
+  if m = 0 then n + 1
+  else if n = 0 then ack (m - 1) 1
+  else ack (m - 1) (ack m (n - 1))
+
+;;
+
+ack 3 4

lib/ocaml/baseline/expected.json

@@ -1,4 +1,5 @@
 {
+  "ackermann.ml": 125,
   "anagrams.ml": 3,
   "bag.ml": 3,
   "balance.ml": 3,