What is up with building DMD (et al.) on Windows?

[Jeremy DeHaan via Digitalmars-d-learn]

On Wednesday, 11 May 2016 at 14:30:44 UTC, Vladimir Panteleev 
wrote:
> On Tuesday, 10 May 2016 at 04:48:23 UTC, Jeremy DeHaan wrote:
>> After DMD is built, other things keep getting built by DMC. I 
>> get more than a few errors due to having an eof character on 
>> the first line of some .h files, or something like that.
>
> I've never seen such an error. Do you have the details?


Late reply, but I was building DMD on a different computer today 
and it reminded me of this.

After dmd.exe is built, I see the command `dmd -run 
checkwhitespace` with a bunch of files following it. The errors I 
see are from this.

Error - file 'aggregate.h' contains windows line endings at line 1
Error - file 'aliasthis.h' contains windows line endings at line 1
Error - file 'arraytypes.h' contains windows line endings at line 
1

And so on.