flambda-backend: Handle exclave in pprintast (#2298)

* handle exclave in pprintast

* fix indentation

* fix test

Author: riaqn

parsing/pprintast.ml

@@ -822,6 +822,10 @@ and expression ?(jane_syntax_parens = false) ctxt f x =
       ({ pexp_desc = Pexp_extension({txt = "extension.local"}, PStr []) },
        [Nolabel, sbody]) ->
         pp f "@[<2>local_ %a@]" (expression ctxt) sbody
+    | Pexp_apply
+      ({ pexp_desc = Pexp_extension({txt = "extension.exclave"}, PStr []) },
+       [Nolabel, sbody]) ->
+        pp f "@[<2>exclave_ %a@]" (expression ctxt) sbody
     | Pexp_apply (e, l) ->
         begin if not (sugar_expr ctxt f x) then
             match view_fixity_of_exp e with

testsuite/tests/parsetree/source_jane_street.ml

@@ -96,6 +96,11 @@ let g () = local_
   let f x y = local_ (x + y) in
   local_ ();;
 
+(* exclaves *)
+let f () = exclave_
+  let f x y = exclave_ (x + y) in
+  ()
+
 (* types *)
 type record =
   { global_ field : int