Actually, there's some use case for these things: you can simulate varargs, and yes the compilation time can be made arbitrary large: https://gist.github.com/toolslive/5957292

  $> time ocamlc vararg.ml
  real    1m9.372s 
  user    1m9.264s
  sys     0m0.044s

Try adding a few a's and see what that gives.