Fix syntax tests. (#6298)

Author: cristianoc

jscomp/syntax/testrunner/res_test.ml

@@ -61,6 +61,8 @@ module OutcomePrinterTests = struct
   let signatureToOutcome structure =
     Lazy.force Res_outcome_printer.setup;
 
+    Clflags.include_dirs :=
+      Filename.concat "lib" "ocaml" :: !Clflags.include_dirs;
     Res_compmisc.init_path ();
     Clflags.nopervasives := true;
     let env = Res_compmisc.initial_env () in

jscomp/syntax/tests/oprint/expected/oprint.resi.txt

@@ -171,9 +171,9 @@ type \"let" = int
 type \"type" = [#"Point🗿"(\"let", float)]
 type t23 = [#1 | #"10space" | #123]
 type exoticUser = {\"let": string, \"type": float}
-type arity1a = (. unit) => int
-type arity1b = (. int) => int
-type arity2 = (. int, int) => int
+type arity1a = unit => int
+type arity1b = int => int
+type arity2 = (int, int) => int
 type obj1<'a> = option<{"a": int}>
 type obj2 = {"a": int}
 type obj3 = {"a": int}
@@ -217,7 +217,7 @@ type permissions = [#644 | #777]
 type numericPolyVarWithPayload = [#1(string) | #2(int, string)]
 let numericPolyVarMatch: [> #1(string) | #2(int, string)]
 let sort: (module(Set.S with type elt = 'a), list<'a>) => list<'a>
-let make_set: (('a, 'a) => int) => module(Set.S with type elt = 'a)
+let make_set: ('a, 'a) => int => module(Set.S with type elt = 'a)
 type picture = string
 module type DEVICE = {
   let draw: picture => unit