Misc: add comments

Author: hhugo

compiler/lib-wasm/generate.ml

@@ -663,6 +663,7 @@ module Generate (Target : Target_sig.S) = struct
     | Constant c -> Constant.translate c
     | Special (Alias_prim _) -> assert false
     | Prim (Extern "caml_alloc_dummy_function", [ _; Pc (Int arity) ]) ->
+        (* Removed in OCaml 5.2 *)
         Closure.dummy ~cps:(effects_cps ()) ~arity:(Targetint.to_int_exn arity)
     | Prim (Extern "caml_alloc_dummy_infix", _) ->
         Closure.dummy ~cps:(effects_cps ()) ~arity:1

compiler/lib/effects.ml

@@ -530,6 +530,7 @@ let rewrite_instr ~st (instr : instr) : instr =
       st.in_cps := Var.Set.add x !(st.in_cps);
       Let (x, Closure (cps_params, cps_cont, None))
   | Let (x, Prim (Extern "caml_alloc_dummy_function", [ size; arity ])) -> (
+      (* Removed in OCaml 5.2 *)
       match arity with
       | Pc (Int a) ->
           Let

compiler/lib/generate.ml

@@ -1497,6 +1497,7 @@ let rec translate_expr ctx loc x e level : (_ * J.statement_list) Expr_builder.t
             let* fields = build_fields fields in
             return (J.EObj fields)
         | Extern "caml_alloc_dummy_function", [ _; size ] ->
+            (* Removed in Ocaml 5.2 *)
             let* i =
               let* cx = access' ~ctx size in
               return