Moving druntime into the DMD repository

[Seb]

On Tuesday, 31 July 2018 at 19:54:20 UTC, Steven Schveighoffer 
wrote:
>
> If anything makes sense, it would be to remove the 
> compiler-dependencies out of druntime into a smaller runtime 
> library that is included in the dmd project. Most of druntime 
> is dependencies for the platform, not the compiler.

Moving object.d to the dmd repository would be rather easy:

https://github.com/dlang/dmd/pull/8529
https://github.com/dlang/druntime/pull/2262

and already help a lot in decoupling both. Maybe that's a 
compromise that can be made?