Function pin_thread 

pub fn pin_thread(cores: &[usize])

Pin the calling thread to the given set of logical CPUs.

Platform behaviour

OS	Semantics
Linux	Sets the CPU affinity mask to the union of the given cores
	via sched_setaffinity. Pass multiple cores to restrict the
	thread to a cluster (e.g. all P-cores).
macOS	Uses the first core as an opaque affinity tag; threads with
	the same tag are co-scheduled by the Mach scheduler. Extra
	cores are ignored (macOS has no multi-core mask).
Other	No-op.

An empty slice is a no-op on all platforms.