small gotcha under Linux

[Ross Paterson]

Perhaps this is well known, but it took me a while to twig to it,
and may be something for binary packagers to watch out for:

A binary produced by ghc-6.7 under Linux 2.6.9 or later will not
run under Linux 2.6.8 or earlier (e.g. monk).  This is because it
will be using CLOCK_PROCESS_CPUTIME_ID/CLOCK_THREAD_CPUTIME_ID,
which are not supported by the older kernels.