Improve the OOP ABI

[Richard (Rikki) Andrew Cattermole]

On 29/09/2023 8:43 PM, FeepingCreature wrote:
> Note that you can still remove TypeInfo that isn't referenced in an 
> executable/library; the only TypeInfo that needs to be exported are 
> those that you actually look at.

The linker can't do that. So you're relying entirely on the compiler for 
this.