While this loses quite a bit of accuracy (although to no apparent
decrease in emulation quality) , it helps avoiding the additional
overhead of the `clock_gettime` syscall (as `CLOCK_MONOTONIC_COARSE`
is forwarded using the mapped time page) and we don't have to do a
HPET timer read for each tick.
This results in a decrease of Serenity boot time from 1h16m down to
42m when running on Serenity.