Support tuple annotations.

Author: cristianoc

src/Exception.re

@@ -276,12 +276,23 @@ let traverseAst = {
       };
       let raisesAnnotationPayload =
         vb.vb_attributes |> Annotation.getAttributePayload((==)("raises"));
-      let exceptions =
-        switch (raisesAnnotationPayload) {
-        | Some(Annotation.StringPayload(s) | Annotation.ConstructPayload(s)) =>
+      let rec getExceptions = payload =>
+        switch (payload) {
+        | Annotation.StringPayload(s) => Exn.fromString(s) |> ExnSet.singleton
+        | Annotation.ConstructPayload(s) =>
           Exn.fromString(s) |> ExnSet.singleton
+        | Annotation.TuplePayload(tuple) =>
+          tuple
+          |> List.map(payload => payload |> getExceptions |> ExnSet.elements)
+          |> List.concat
+          |> ExnSet.of_list
         | _ => ExnSet.empty
         };
+      let exceptions =
+        switch (raisesAnnotationPayload) {
+        | None => ExnSet.empty
+        | Some(payload) => payload |> getExceptions
+        };
       Hashtbl.replace(valueBindingsTable, Ident.name(id), exceptions);
       let res = super.value_binding(self, vb);
       let raiseSet = currentEvents^ |> Event.combine;