Fix issue with formatting comment on labelled argument in uncurried mode

Fixes #6094

Author: cristianoc

jscomp/ml/ast_uncurried.ml

@@ -50,7 +50,7 @@ let rec attributes_to_arity (attrs : Parsetree.attributes) =
 let uncurriedFun ~loc ~arity funExpr =
     Ast_helper.Exp.construct ~loc
       ~attrs:(arity_to_attributes arity)
-      { txt = Lident "Function$"; loc }
+      (Location.mknoloc (Longident.Lident "Function$"))
       (Some funExpr)
 
 let exprIsUncurriedFun (expr : Parsetree.expression) =

res_syntax/tests/printer/expr/Uncurried.res

@@ -4,4 +4,11 @@ let add3 = (x,y,z) => x+y+z
 
 let triangle = 3 |> add3(1,2) |> add3(4,5)
 
-let () = 3 |> ignore
+let () = 3 |> ignore
+
+let foo = (/* ddd */ x) => x
+
+let f = (
+  // comment
+  ~a,
+) => a

res_syntax/tests/printer/expr/expected/Uncurried.res.txt

@@ -5,3 +5,10 @@ let add3 = (x, y, z) => x + y + z
 let triangle = add3(4, 5, add3(1, 2, 3))
 
 let () = ignore(3)
+
+let foo = /* ddd */ x => x
+
+let f = (
+  // comment
+  ~a,
+) => a