This is also needed in order to make the requested number of CPUs
appear. For now we don't reroute to the original sysconf() call so
we return -1,EINVAL for all other info.
The wrapper mode allows to present itself as LD_PRELOAD before loading
haproxy, which is often more convenient since it allows to pass the
number of CPUs in argument. However, this mode is no longer supported by
modern glibcs, so a future patch will come to implement a trick that was
tested to work at least on x86.
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.
