const runtime.scavengeReservationShards

2 uses

	runtime (current package)
		mgcscavenge.go#L99: 	scavengeReservationShards = 64
		mgcscavenge.go#L532: 	p.scav.reservationBytes = alignUp(p.inUse.totalBytes, pallocChunkBytes) / scavengeReservationShards