py/obj.h: Explicitly cast args to uint32_t in MP_OBJ_FUN_MAKE_SIG.

For architectures where size_t is less than 32 bits (eg 16 bits) the args
must be casted to uint32_t so the left shift will work.  For architectures
where size_t is greater than 32 bits (eg 64 bits) this new casting will not
lose any bits because the end result must anyway fit in a uint32_t.

py/obj.h

@@ -278,7 +278,7 @@ typedef struct _mp_rom_obj_t { mp_const_obj_t o; } mp_rom_obj_t;
 #define MP_DECLARE_CONST_FUN_OBJ_KW(obj_name) extern const mp_obj_fun_builtin_var_t obj_name
 
 #define MP_OBJ_FUN_ARGS_MAX (0xffff) // to set maximum value in n_args_max below
-#define MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, takes_kw) (((n_args_min) << 17) | ((n_args_max) << 1) | ((takes_kw) ? 1 : 0))
+#define MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, takes_kw) ((uint32_t)((((uint32_t)(n_args_min)) << 17) | (((uint32_t)(n_args_max)) << 1) | ((takes_kw) ? 1 : 0)))
 
 #define MP_DEFINE_CONST_FUN_OBJ_0(obj_name, fun_name) \
     const mp_obj_fun_builtin_fixed_t obj_name = \

py/runtime.h

@@ -79,7 +79,7 @@ int mp_print_mp_int(const mp_print_t *print, mp_obj_t x, int base, int base_char
 
 void mp_arg_check_num_sig(size_t n_args, size_t n_kw, uint32_t sig);
 static inline void mp_arg_check_num(size_t n_args, size_t n_kw, size_t n_args_min, size_t n_args_max, bool takes_kw) {
-    mp_arg_check_num_sig(n_args, n_kw, (uint32_t)MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, takes_kw));
+    mp_arg_check_num_sig(n_args, n_kw, MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, takes_kw));
 }
 void mp_arg_parse_all(size_t n_pos, const mp_obj_t *pos, mp_map_t *kws, size_t n_allowed, const mp_arg_t *allowed, mp_arg_val_t *out_vals);
 void mp_arg_parse_all_kw_array(size_t n_pos, size_t n_kw, const mp_obj_t *args, size_t n_allowed, const mp_arg_t *allowed, mp_arg_val_t *out_vals);