Fixed keyword removed despite skip directives

[zyzy811]

public unsafe struct Test
{
    public fixed byte data[8];
}

After running the cleaning activity document:
public unsafe struct Test
{
public byte data[8];
}
This caused an error in the code

[Nitload-NSI]

#1047

I have opened this issue months before.
But as you see, this repo hasn't been maintained for a very long time, so maybe there is no better solution to it than using another plugin with similar function.