add async example for dynamic import

Author: mununki

jscomp/test/Import.js

@@ -6,16 +6,14 @@ var each = import("../../lib/js/belt_List.js").then(function (m) {
       return m.forEach;
     });
 
-function eachInt(list, f) {
-  var arg1 = function (each) {
-    return Promise.resolve(Curry._2(each, list, f));
-  };
-  return each.then(arg1);
-}
-
 var beltAsModule = import("../../lib/js/belt_List.js");
 
+async function eachInt(list, f) {
+  var each$1 = await each;
+  return Curry._2(each$1, list, f);
+}
+
 exports.each = each;
-exports.eachInt = eachInt;
 exports.beltAsModule = beltAsModule;
+exports.eachInt = eachInt;
 /* No side effect */

jscomp/test/Import.res

@@ -6,3 +6,8 @@ let eachInt = (list: list<int>, f: int => unit) =>
 module type BeltList = module type of Belt.List
 
 let beltAsModule = Js.import(module(Belt.List: BeltList))
+
+let eachInt = async (list: list<int>, f: int => unit) => {
+  let each = await each
+  list->each(f)
+}