flambda-backend: Backport first part of ocaml/ocaml PR10498 (#737)

Author: mshinwell

asmcomp/cmm_helpers.ml

@@ -2002,7 +2002,7 @@ let send_function (arity, mode) =
   let cache = cache in
   let fun_name = send_function_name arity mode in
   let fun_args =
-    [obj, typ_val; tag, typ_int; cache, typ_val]
+    [obj, typ_val; tag, typ_int; cache, typ_addr]
     @ List.map (fun id -> (id, typ_val)) (List.tl args) in
   let fun_dbg = placeholder_fun_dbg ~human_name:fun_name in
   Cfunction