llvm.ffi: make the binding linux-specific for now
llvm.ffi: make the binding linux-specific for now

factor/factor,mrjbq7/factor,bpollack/factor,mrjbq7/factor,AlexIljin/factor,tgunr/factor,bpollack/factor,mrjbq7/factor,bpollack/factor,factor/factor,tgunr/factor,AlexIljin/factor,AlexIljin/factor,AlexIljin/factor,tgunr/factor,tgunr/factor,bpollack/factor,mrjbq7/factor,factor/factor,bpollack/factor,factor/factor,AlexIljin/factor,mrjbq7/factor,bpollack/factor,AlexIljin/factor,tgunr/factor,tgunr/factor,mrjbq7/factor,bpollack/factor,factor/factor,factor/factor,AlexIljin/factor