Bug: Unicode character of zsh module will become weird characters

["Wu, Zhenyu" <wuzhenyu@xxxxxxxx>]

Excuse me:

Reproduce procedures:

```zsh
% git clone --depth=1 https://github.com/zsh-users/zsh
% cd zsh
% sed -i 's/strparam = ztrdup("example");/strparam = ztrdup("你好");/' Src/Modules/example.c
% autoreconf -vif
% ./configure
% make
```

Actual behavior:

```zsh
% zsh -f
laptop% module_path+=( $PWD/Src/Modules )
laptop% zmodload example
The example module has now been set up.
laptop% echo ${(q)exstr}
$'\344'$'\275'\好
laptop%
```

Expected behavior:

```zsh
% zsh -f
laptop% module_path+=( $PWD/Src/Modules )
laptop% zmodload example
The example module has now been set up.
laptop% echo ${(q)exstr}
你好
laptop%
```

Is it a bug? TIA!

-- 
Best Regards
Wu, Zhenyu