[SAoC 2021] Replace druntime Hooks with Templates: Milestone 2, Week 1

[Imperatorn]

On Friday, 22 October 2021 at 22:18:22 UTC, Teodor Dutu wrote:
> Hi,
>
> The objectives of this milestone is to reach and implement a 
> decision for the `_d_arrayctor` lowering and to translate the 
> lowerings to `_d_arrayappendT` and `_d_arrayappendcTX` into 
> templates.
>
> [...]

👏