minimal object.d implementation that allows classes

[Jean-Louis Leroy]

On Thursday, 7 December 2017 at 15:34:09 UTC, Steven 
Schveighoffer wrote:
> On 12/7/17 10:21 AM, Jean-Louis Leroy wrote:
>> Bar.classinfo.vtbl.ptr[Bar.classinfo.vtbl.length] = 
>> cast(void*) 0x123456;
>
> This is a buffer overflow, why are you doing this specifically?
>
> -Steve

It's not an overflow because of the call to `reserve`. It is part 
of an experiment related to supporting user-defined per-class 
metadata by extending the vtable.