fix instances of @U that should be @u0

jscomp/others/node_fs.ml

@@ -67,7 +67,7 @@ module Watch = struct
     f:
       ([ `change of
          (string (*eventType*) -> Node.string_buffer (* filename *) -> unit[@u])
-       | `error of (unit -> unit[@u]) ]
+       | `error of (unit -> unit[@u0]) ]
       [@mel.string]) ->
     t = "on"
   [@@mel.send]

jscomp/runtime/caml_external_polyfill.ml

@@ -28,7 +28,7 @@ open struct
   module Js = Js_internal
 end
 
-let getGlobalThis : (unit -> global[@u]) =
+let getGlobalThis : (unit -> global[@u0]) =
   [%raw
     {| function(){
   if (typeof globalThis !== 'undefined') return globalThis;

jscomp/stdlib/camlinternalLazy.ml

@@ -36,8 +36,8 @@ type 'a concrete = {
 
 exception Undefined
 
-external fnToVal : (unit -> 'a [@u]) -> 'a = "%identity"
-external valToFn :  'a -> (unit -> 'a [@u])  = "%identity"
+external fnToVal : (unit -> 'a [@u0]) -> 'a = "%identity"
+external valToFn :  'a -> (unit -> 'a [@u0])  = "%identity"
 external castToConcrete : 'a lazy_t -> 'a concrete   = "%identity"
 external of_concrete : 'a concrete -> 'a lazy_t   = "%identity"
 
@@ -46,15 +46,15 @@ let is_val (type a ) (l : a lazy_t) : bool =
 
 
 
-let forward_with_closure (type a ) (blk : a concrete) (closure : unit -> a [@u]) : a =
-  let result = closure () [@u] in
+let forward_with_closure (type a ) (blk : a concrete) (closure : unit -> a [@u0]) : a =
+  let result = closure () [@u0] in
   (* do set_field BEFORE set_tag *)
   blk.value <- result;
   blk.tag<- true;
   result
 
 
-let raise_undefined =  (fun [@u] () -> raise Undefined)
+let raise_undefined =  (fun [@u0] () -> raise Undefined)
 
 (* Assume [blk] is a block with tag lazy *)
 let force_lazy_block (type a ) (blk : a t) : a  =
@@ -64,7 +64,7 @@ let force_lazy_block (type a ) (blk : a t) : a  =
   try
     forward_with_closure blk closure
   with e ->
-    blk.value <- fnToVal (fun [@u] () -> raise e);
+    blk.value <- fnToVal (fun [@u0] () -> raise e);
     raise e
 
 

jscomp/test/demo.ml

@@ -94,7 +94,7 @@ let ui_layout
       with  e -> ()
     end;
     let fmt v = toFixed v 2 in
-    set_interval (fun [@u] () ->
+    set_interval (fun [@u0] () ->
 
       grid##dataSource #=
         ( array_map data (fun [@u] {ticker; price } ->

jscomp/test/demo_binding.ml

@@ -102,7 +102,7 @@ class type textArea =
   end[@u]
 
 
-external set_interval : (unit -> unit [@u]) -> float -> unit  =  "setInterval"
+external set_interval : (unit -> unit [@u0]) -> float -> unit  =  "setInterval"
      [@@mel.module "@runtime", "Runtime"]
 
 external toFixed : float -> int -> string = "toFixed" [@@mel.send]

jscomp/test/gpr_2682_test.ml

@@ -52,9 +52,8 @@ end
 ;;   forIn   [%obj{x = 3 ; y = 3}]  (fun[@u] x -> Js.log x)
 
 
-let f3  : unit -> bool [@u] = [%raw"()=>true"]
+let f3  : unit -> bool [@u0] = [%raw"()=>true"]
 
-let bbbb  = f3 () [@u]
+let bbbb  = f3 () [@u0]
 
 ;;assert (bbbb)
-

jscomp/test/http_types.ml

@@ -23,7 +23,7 @@ class type _resp =
 type resp = _resp Js.t
 class type _server =
   object
-    method listen : int ->  string -> (unit -> unit [@u]) -> unit
+    method listen : int ->  string -> (unit -> unit [@u0]) -> unit
   end[@u]
 type server = _server Js.t
 class type _http =

jscomp/test/mt.ml

@@ -1,4 +1,4 @@
-external describe : string -> (unit -> unit[@u]) -> unit = "describe"
+external describe : string -> (unit -> unit[@u0]) -> unit = "describe"
 
 external it : string -> (unit -> unit[@mel.uncurry]) -> unit = "it"
 external it_promise : string -> (unit -> _ Js.Promise.t [@mel.uncurry]) -> unit = "it"
@@ -37,7 +37,7 @@ let from_suites name (suite :  (string * ('a -> unit)) list) =
   match Array.to_list Node.Process.process##argv with
   | _cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           List.iter (fun (name, code) -> it name code) suite)
 
   | _ -> ()
@@ -96,7 +96,7 @@ let from_pair_suites name (suites :  pair_suites) =
   match Array.to_list Node.Process.process##argv with
   | _cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           suites |>
           List.iter (fun (name, code) ->
               it name (fun _ ->
@@ -111,7 +111,7 @@ let from_promise_suites name (suites : (string * _ Js.Promise.t ) list) =
   match Array.to_list Node.Process.process##argv with
   | _cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           suites |>
           List.iter (fun (name, code) ->
               it_promise name (fun _ ->

jscomp/test/ocaml_typedtree_test.ml

@@ -11621,7 +11621,7 @@ end = struct
 
 
 
-external describe : string -> (unit -> unit[@u]) -> unit = "describe"
+external describe : string -> (unit -> unit[@u0]) -> unit = "describe"
 
 
 external it : string -> (unit -> unit[@mel.uncurry]) -> unit = "it"
@@ -11677,7 +11677,7 @@ let from_suites name (suite :  (string * ('a -> unit)) list) =
   match Array.to_list Node.Process.process##argv with
   | cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           List.iter (fun (name, code) -> it name code) suite)
 
   | _ -> ()
@@ -11736,7 +11736,7 @@ let from_pair_suites name (suites :  pair_suites) =
   match Array.to_list Node.Process.process##argv with
   | cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           suites |>
           List.iter (fun (name, code) ->
               it name (fun _ ->
@@ -11751,7 +11751,7 @@ let from_promise_suites name (suites : (string * _ Js.Promise.t ) list) =
   match Array.to_list Node.Process.process##argv with
   | cmd :: _ ->
     if is_mocha () then
-      describe name (fun [@u] () ->
+      describe name (fun [@u0] () ->
           suites |>
           List.iter (fun (name, code) ->
               it_promise name (fun _ ->