How to enable log in release in Rust (ckb-std)

[XuJiandong]

We can use debug! macro from ckb-std to print log. It can only work in debug mod not in release mode. Here is the simple code snippets which can print log in release mode:

use alloc::format;
use ckb_std::{default_alloc, syscalls::debug};
debug(format!("hello, world"));

Note: it's debug syscall, not macro debug!.