Moving druntime into the DMD repository

[Radu]

On Friday, 27 July 2018 at 11:03:50 UTC, Seb wrote:
> This a thread to explore whether it would be feasible to do so.
>
> Motivation
> ----------
>
> [...]

Druntime is not exclusively DMD. For example when porting to 
other platforms or cruntimes is already hard because of the sync 
and merge you need to do when you move your changes upstream. 
Most of the time those changes have nothing to do with dmd.

Having dmd source internwined with druntime will make things even 
harder.

Better find a solution on the CI server side rather then merge 
dmd with druntime.