refactor: use inline record for J.Try (#1196)

jscomp/core/j.ml

@@ -309,7 +309,11 @@ and statement_desc =
       default : block option;
     }
   | Throw of expression
-  | Try of block * (exception_ident * block) option * block option
+  | Try of {
+      body : block;
+      catch : (exception_ident * block) option;
+      finally : block option;
+    }
   | Debugger
 
 and expression = {

jscomp/core/js_dump.ml

@@ -1244,7 +1244,7 @@ and statement_desc top cxt (s : J.statement_desc) : cxt =
           cxt)
   (* There must be a space between the return and its
      argument. A line return would not work *)
-  | Try (b, ctch, fin) ->
+  | Try { body = b; catch = ctch; finally = fin } ->
       vgroup cxt 0 (fun _ ->
           string cxt L.try_;
           space cxt;

jscomp/core/js_stmt_make.ml

@@ -383,7 +383,7 @@ let for_ ?comment for_ident_expression finish_ident_expression id direction
   }
 
 let try_ ?comment ?with_ ?finally body : t =
-  { statement_desc = Try (body, with_, finally); comment }
+  { statement_desc = Try { body; catch = with_; finally }; comment }
 
 (* TODO:
     actually, only loops can be labelled