Pass pointer to va for Windows.
@@ -1685,7 +1685,7 @@ static void interp (MIR_context_t ctx, MIR_item_t func_item, va_list va, MIR_val
case MIR_T_BLK4:
case MIR_T_BLK5: {
arg_vals[i].a = alloca (arg_vars[i].size);
-#if defined(__PPC64__) || defined(__aarch64__)
+#if defined(__PPC64__) || defined(__aarch64__) || defined(_WIN32)
va_block_arg_builtin (arg_vals[i].a, &va, arg_vars[i].size, type);
#else
va_block_arg_builtin (arg_vals[i].a, va, arg_vars[i].size, type);
