[D-runtime] [dmd-internals] why core/thread.d and core/thread.di in druntime?

[Walter Bright]

On 1/9/2013 10:22 AM, Don Clugston wrote:
> Personally I don't think we should have any .di files in there, whatsoever. 
> They just cause problems, for NO BENEFIT. We don't want have trade secrets we 
> want to hide, and .di files serve no other purpose.

One example: do we really want to recompile the garbage collector for every D 
program?