Sending SystemPowerReset request to local Target while A3 fault asserted causes system to not power on

While troubleshooting https://github.com/oxidecomputer/hardware-sidecar/issues/785 a SystemPowerReset request was sent to the Target to try and determine if the A3 power fault bit would get cleared. The system was powered off as expected but did not turn back on. Pressing the reset button also did not power on the system. A reset of Ignition by removing power from the chassis was required to bring the system back.

Presumably the system power fault monitor triggered a MAPO event on power up keeping the system from powering up. Some code reading should be done to determine why this occurred and whether or not this is a bug and requires a fix.