[ocaml] aliasing sexp_{list,option} doesn't work anymore

Summary:
That trick briefly worked when it was introduced but I think a change in
merlin broke it again as I see "sexp_list", "sexp_option" in the types
shown by merlin again. Disgusting!

Remove useless hack. Also referring to types such as `sexp_list` is
deprecated in core v13 for some reason.

Reviewed By: jberdine

Differential Revision: D19861586

fbshipit-source-id: 1c4c3af13

infer/src/istd/IStd.ml

@@ -26,12 +26,6 @@ let invalid_argf _ : [`use_Logging_die_instead] = assert false
 
 let exit = `In_general_prefer_using_Logging_exit_over_Pervasives_exit
 
-(* prevent merlin et al. from showing ['a sexp_list] everywhere a list type is used *)
-type 'a list = 'a sexp_list
-
-(* prevent merlin et al. from showing ['a sexp_option] everywhere an option type is used *)
-type 'a option = 'a sexp_option
-
 [@@@warning "+32"]
 
 module ANSITerminal : module type of ANSITerminal = struct