dtrace,etw support levels

[jasnell]

The @nodejs/diagnostics WG met this last week in Munich. Among the bits discussed were the current state of the DTrace and ETW system trace support within core. It was decided that continued support for the existing DTrace and ETW probes would be limited to "Best Effort" given that those probe points have been largely unmaintained for quite some time. This would mean that any breakage to those bits would not be block releases, particularly since there are no tests covering those probe points to ensure that they are properly functioning.

The @nodejs/diagnostics working group wanted, however, to at least put out a notice and a call for help: If you have an interest in seeing the system trace probes maintained and fully supported beyond Best Effort, we can create a system-trace team. This would require the creation of proper CI tests to validate that the probe points are continuing to function correctly.