Backport AST changes to Ppat_unpack (#2774)

* parser-std: Backport Ppat_unpack

Also backport the `map_loc` change in `Ast_mapper`.

* parser-ext: Backport Ppat_unpack

We already did a similar change in the past, the parsetree doesn't
change.

* parser-ext: Backport Ast_mapper map_loc changes

* Disable rewriting rule for Ppat_unpack

It is no longer valid to rewrite:

    ((module M) : (module S))

into:

    (module M : S)

Author: Julow

CHANGES.md

@@ -8,7 +8,7 @@ profile. This started with version 0.26.0.
 
 ### Highlight
 
-- Support OCaml 5.5 syntax (#2772, @Julow)
+- Support OCaml 5.5 syntax (#2772, #2774, @Julow)
 
 - \* Update Odoc's parser to 3.0 (#2757, @Julow)
   The indentation of code-blocks containing OCaml code is reduced by 2 to avoid

lib/Extended_ast.ml

@@ -296,13 +296,6 @@ module Parse = struct
       | {ppat_desc= Ppat_record (fields, flag); _} as e ->
           let fields = List.map ~f:(pat_record_field m) fields in
           {e with ppat_desc= Ppat_record (fields, flag)}
-      (* [(module M) : (module T)] -> [(module M : T)] *)
-      | { ppat_desc=
-            Ppat_constraint
-              ( {ppat_desc= Ppat_unpack (name, None); ppat_attributes= []; _}
-              , {ptyp_desc= Ptyp_package pt; ptyp_attributes= []; _} )
-        ; _ } as p ->
-          {p with ppat_desc= Ppat_unpack (name, Some pt)}
       | {ppat_desc= Ppat_tuple (l, oc); _} as p ->
           let l = List.map ~f:(pat_tuple_elt m) l in
           {p with ppat_desc= Ppat_tuple (l, oc)}

test/passing/refs.ahrefs/first_class_module.ml.ref

@@ -122,3 +122,16 @@ let x = (module M : S)
 module T = (val (x : (module S)))
 
 let _ = (module Int : T[@foo])
+
+let _ = fun ((module X) : (module M.S with type a = a)) -> X.v
+let _ = fun (module X : M.S with type a = a) -> X.v
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+    (module M1 : MS.S), ((module M2) : (module MS.S)))
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+    ((module M1) : (module MS.S)), ((module M2) : (module MS.S)))

test/passing/refs.ahrefs/source.ml.ref

@@ -4672,13 +4672,13 @@ module B' = B
 class b : B.a =
   object
     method a : 'a. 'a M.s -> 'a =
-      fun (type a) (module X : M.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M.S with type a = a)) -> X.v
   end
 
 class b' : B.a =
   object
     method a : 'a. 'a M'.s -> 'a =
-      fun (type a) (module X : M'.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M'.S with type a = a)) -> X.v
   end
 module type FOO = sig
   type t

test/passing/refs.default/first_class_module.ml.ref

@@ -115,3 +115,15 @@ let x = (module M : S)
 module T = (val (x : (module S)))
 
 let _ = (module Int : T[@foo])
+let _ = fun ((module X) : (module M.S with type a = a)) -> X.v
+let _ = fun (module X : M.S with type a = a) -> X.v
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+      ((module M1 : MS.S), ((module M2) : (module MS.S))))
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+      (((module M1) : (module MS.S)), ((module M2) : (module MS.S))))

test/passing/refs.default/source.ml.ref

@@ -4585,13 +4585,13 @@ module B' = B
 class b : B.a =
   object
     method a : 'a. 'a M.s -> 'a =
-      fun (type a) (module X : M.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M.S with type a = a)) -> X.v
   end
 
 class b' : B.a =
   object
     method a : 'a. 'a M'.s -> 'a =
-      fun (type a) (module X : M'.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M'.S with type a = a)) -> X.v
   end
 
 module type FOO = sig

test/passing/refs.janestreet/first_class_module.ml.ref

@@ -123,3 +123,17 @@ let x = (module M : S)
 module T = (val (x : (module S)))
 
 let _ = (module Int : T[@foo])
+let _ = fun ((module X) : (module M.S with type a = a)) -> X.v
+let _ = fun (module X : M.S with type a = a) -> X.v
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+    (module M1 : MS.S), ((module M2) : (module MS.S)))
+;;
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+    ((module M1) : (module MS.S)), ((module M2) : (module MS.S)))
+;;

test/passing/refs.janestreet/source.ml.ref

@@ -5078,12 +5078,14 @@ module B' = B
 
 class b : B.a =
   object
-    method a : 'a. 'a M.s -> 'a = fun (type a) (module X : M.S with type a = a) -> X.v
+    method a : 'a. 'a M.s -> 'a =
+      fun (type a) ((module X) : (module M.S with type a = a)) -> X.v
   end
 
 class b' : B.a =
   object
-    method a : 'a. 'a M'.s -> 'a = fun (type a) (module X : M'.S with type a = a) -> X.v
+    method a : 'a. 'a M'.s -> 'a =
+      fun (type a) ((module X) : (module M'.S with type a = a)) -> X.v
   end
 
 module type FOO = sig

test/passing/refs.ocamlformat/first_class_module.ml.ref

@@ -118,3 +118,17 @@ let x = (module M : S)
 module T = (val (x : (module S)))
 
 let _ = (module Int : T[@foo])
+
+let _ = fun ((module X) : (module M.S with type a = a)) -> X.v
+
+let _ = fun (module X : M.S with type a = a) -> X.v
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+      ((module M1 : MS.S), ((module M2) : (module MS.S))) )
+
+let _ =
+  let module MS = struct module type S = sig end end in
+  (fun _ -> ()) (fun (module M1 : MS.S) ((module M2) : (module MS.S)) ->
+      (((module M1) : (module MS.S)), ((module M2) : (module MS.S))) )

test/passing/refs.ocamlformat/source.ml.ref

@@ -5185,13 +5185,13 @@ module B' = B
 class b : B.a =
   object
     method a : 'a. 'a M.s -> 'a =
-      fun (type a) (module X : M.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M.S with type a = a)) -> X.v
   end
 
 class b' : B.a =
   object
     method a : 'a. 'a M'.s -> 'a =
-      fun (type a) (module X : M'.S with type a = a) -> X.v
+      fun (type a) ((module X) : (module M'.S with type a = a)) -> X.v
   end
 
 module type FOO = sig