Unused druntime code: Barrier, ReadWriteMutex, Condition

[Denis Feklushkin]

On Tuesday, 16 June 2026 at 10:41:00 UTC, Richard (Rikki) Andrew 
Cattermole wrote:

> So version it off like we do with bindings.
>
> There is no reason to break existing code when we can do that.
>
> ```d
> version(FreeRTOS)
> 	version = NoBarrier;
> ```

But this will break existing code which using Barrier when 
cross-compiling for FreeRTOS :-)