Core.atomic: Fencing?

[dsimcha]

== Quote from Iain Buclaw (ibuclaw at ubuntu.com)'s article
> On top of that, GCC targets will (*WIP*) be using builtin atomic load/cas routines
> for architectures that support. And I'm pretty certain LDC does the same (I
> believe it's implemented in Tango).
> Regards

I assume the implication is that the GCC builtin atomics act as full barriers on
all architectures?