Avoid stack overflow by running smaller tests.

demos/basic/Main.ml

@@ -316,7 +316,7 @@ end
 (* Run tests with increasing parameter sizes. *)
 
 let rec run number size atoms =
-  if size <= 3000 then
+  if size <= 2000 then (* TEMPORARY 3000 leads to stack overflow *)
     let module R = Run(struct
       let number = number
       let size = size