Migrating an existing more modern GC to D's gc.d

[Per Nordlöw]

On Thursday, 24 May 2018 at 13:13:03 UTC, Steven Schveighoffer 
wrote:
> Really though, the issues with D's GC are partly to blame from 
> the language itself rather than the GC design. Having certain 
> aspects of the language precludes certain GCs. Java as a 
> language is much more conducive to more advanced GC designs.

I'm hoping for a tough long-term deprecation process that 
alleviates these issues eventhough they will cause big breakage. 
I believe it will be worth it.