betterC shared static ctor

[Mike Parker]

On Wednesday, 21 July 2021 at 08:11:06 UTC, vit wrote:
> Is it possible to call all shared static ctors in betterC?
>
> ```d
> //-betterC
>
> static immutable int i;
>
> shared static this(){
> 	i = 42;
> }
> extern(C) void main(){
>     assert(i != 42);
>
> }
> ```

These rely on DRuntime, which is not linked in betterC mode. 
You'll need to use the `crt_constructor` and `crt_destructor` 
pragmas:

https://dlang.org/spec/pragma.html#crtctor

Apply them to any `extern(C) function for static ctor/dtor 
behavior.