DEV: ncpu: add a simple utility to help with NUMA development

DEV: ncpu: add a simple utility to help with NUMA development

Collecting captures of /sys isn't sufficient for NUMA development because
haproxy detects the number of CPUs at boot time and will not be able to
inspect more than this number. Let's just have a small utility to report
a fake number of CPUs, that will be loaded using LD_PRELOAD. It checks
the NCPU variable if it exists and will present this number of CPUs, or
if it does not exist, will expose the maximum supported number.