consistency of CPU time units

[heckj]

Exploring benchmarks, I was exploring setting
Benchmark.defaultConfiguration.timeUnits = .microseconds. It does exactly what it says for the metric Time (wall clock), but doesn't appear to do anything with Time (system CPU) (μs), Time (total CPU) (μs), or Time (user CPU) (μs). And in some cases, I'm seeing the Time (system CPU) come back in ns regardless of what I've chosen.

I suspect it'll be a little easier to track if you can either nail is down explicitly across the board (and sometimes forcing a "round to 0" result), or just letting them float with whatever comes back from the metric gathering system and floating with the relevant range.