Add cram tests in regressin directory

Signed-off-by: Kakadu <Kakadu@pm.me>

regression/gen.ml

@@ -0,0 +1,35 @@
+(* Run as `ocaml gen.ml` *)
+
+let count = 1000
+
+let () =
+  Out_channel.with_open_text "dune" (fun dunech ->
+      let dprintfn fmt = Format.kasprintf (Printf.fprintf dunech "%s\n") fmt in
+      dprintfn "; This file was autogenerated\n";
+      dprintfn "(cram (deps ../src/Driver.exe ../runtime/Std.i ../runtime32/Std.i))\n";
+
+      for i = 0 to count - 1 do
+        let cram_buf = Buffer.create 100 in
+        let cram_printfn fmt =
+          Format.kasprintf (Printf.bprintf cram_buf "%s\n") fmt
+        in
+        let cram_file = ref (Printf.sprintf "test%03d.t" i) in
+        let lama_file = ref (Printf.sprintf "test%03d.lama" i) in
+        let input_file = ref (Printf.sprintf "test%03d.input" i) in
+
+
+        let found =
+          if Sys.file_exists !lama_file then (
+            cram_printfn
+              "  $ LAMA=../runtime ../src/Driver.exe -i test%03d.lama < \
+               test%03d.input"
+              i i;
+            true)
+          else   false
+        in
+        if found then (
+          dprintfn "(cram (applies_to test%03d)"            i;
+          dprintfn "  (deps %s %s))" !lama_file !input_file;
+          Out_channel.with_open_text !cram_file (fun ch ->
+              output_string ch (Buffer.contents cram_buf)))
+      done)