add test for multiple await in function

Author: mununki

jscomp/test/Import.js

@@ -47,3 +47,9 @@ let f1 = async () => {
   module M3 = await (Belt.List: BeltList)
   M3.forEach
 }
+
+let f2 = async () => {
+  module M3 = await (Belt.List: BeltList)
+  module M4 = await (Belt.List: BeltList)
+  (M3.forEach, M4.forEach)
+}