The thread_apis tests of the RUNTIME_STATS feature weren't really
testing the right behavior.
+ It assumed that accounting would only happen at context switch time
and required that the returned values not change for running threads
(even CLEARLY running threads like _current!). But that's not a
documented feature! It's actually sort of a wart that we'd like to
be able to fix (and have fixed, the new backend returns realtime
values so you can track CPU-bound processes on another CPU).
+ It assumed that k_thread_runtime_stats_all_get() would return time
that includes idle time (or conversely it forgot that
k_thread_foreach enumerates over idle threads). This was sort of a
bug in the original (because it means that the result is always the
system uptime multiplied by the number of CPUs)
Broadly, instead of testing the result of a "time" function for
equality (never a good idea) test it via appropriate bounds given the
usage.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>