parse: use MIN/MAXDOUBLE instead of some representation of NAN

Doesn't always work for C99.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
clock: hardwire tsc as unreliable on Solaris for now

Need to double check the cpuid test, it probably only is reliable
on Intel. Need to check the CPU vendor and flags appropriately.

Signed-off-by: Jens Axboe <axboe@kernel.dk>