An easy phobos i/o bug to fix

[starcanopy]

On Monday, 27 July 2020 at 15:19:44 UTC, Steven Schveighoffer 
wrote:
> If anyone is using windows and std.stdio.File.rawWrite, it's 
> insanely slow. And it's an easy fix. See 
> https://issues.dlang.org/show_bug.cgi?id=7033
>
> I don't use Windows, so I probably won't get around to fixing 
> this. But ping me if you make a PR, I will review it.
>
> -Steve

So, upon opening a File, save the mode into a field, and only 
execute the current behavior iff the mode isn't binary?