[istd] banish sexp_{list,option}

Summary:
It's annoying to see `sexp_list` everywhere instead of `list`, eg in
merlin.

See also D17907938.

Reviewed By: ngorogiannis

Differential Revision: D17927994

fbshipit-source-id: 84599e8bc

infer/src/istd/IStd.ml

@@ -26,6 +26,12 @@ 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