Make the tests for uncaught exceptions more portable

Author: vouillon

compiler/tests-check-prim/main.output

@@ -197,6 +197,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-check-prim/main.output5

@@ -150,6 +150,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-check-prim/unix-unix.output

@@ -306,6 +306,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-check-prim/unix-unix.output5

@@ -261,6 +261,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-check-prim/unix-win32.output

@@ -271,6 +271,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-check-prim/unix-win32.output5

@@ -227,6 +227,7 @@ caml_build_symbols
 caml_is_printable
 caml_maybe_print_stats
 caml_register_global
+caml_unregister_named_value
 
 From +str.js:
 caml_str_initialize

compiler/tests-jsoo/bin/dune

@@ -1,6 +1,7 @@
 (executables
  (names error1 error2 error3)
- (modes byte js))
+ (modes byte js)
+ (libraries js_of_ocaml))
 
 (rule
  (target error1.actual)

compiler/tests-jsoo/bin/error1.ml

@@ -1,8 +1,8 @@
+external unregister : string -> unit = "caml_unregister_named_value"
+
 let () =
   match Array.to_list Sys.argv with
-  | _ :: "unregister" :: _ ->
-      let null = Array.unsafe_get [| 1 |] 1 in
-      Callback.register "Printexc.handle_uncaught_exception" null
+  | _ :: "unregister" :: _ -> unregister "Printexc.handle_uncaught_exception"
   | _ -> ()
 
 exception D of int * string * Int64.t

compiler/tests-jsoo/bin/error2.ml

@@ -1,10 +1,10 @@
+external unregister : string -> unit = "caml_unregister_named_value"
+
 let () =
   (* Make sure Printexc is linked *)
   let _ = Printexc.to_string Not_found in
   match Array.to_list Sys.argv with
-  | _ :: "unregister" :: _ ->
-      let null = Array.unsafe_get [| 1 |] 1 in
-      Callback.register "Printexc.handle_uncaught_exception" null
+  | _ :: "unregister" :: _ -> unregister "Printexc.handle_uncaught_exception"
   | _ -> ()
 
 [@@@ocaml.warning "-8"]

compiler/tests-jsoo/bin/error3.ml

@@ -1,10 +1,8 @@
+external unregister : string -> unit = "caml_unregister_named_value"
+
 let () =
   match Array.to_list Sys.argv with
-  | _ :: "unregister" :: _ ->
-      let null = Array.unsafe_get [| 1 |] 1 in
-      Callback.register "Printexc.handle_uncaught_exception" null
+  | _ :: "unregister" :: _ -> unregister "Printexc.handle_uncaught_exception"
   | _ -> ()
 
-let null : _ -> _ -> _ = Array.unsafe_get [||] 0
-
-let _ = null 1 2
+let _ = (Obj.magic Js_of_ocaml.Js.null : int -> int -> unit) 1 2