I found this chunk when I did today pull into my repo and got another conflict. This was written when I debugged ACPI_DMAR and got some NMIs. One of the theories was that a device reacted badly to DMA fault which resulted in transaction abort and reported that as NMI. It appeared to be false, and this code allowed to determine that.
This is very primitive thing, it only allows to inspect the PCI error state and AER error state, dump the log and clear errors, from ddb. You see that pci_print_faulted_dev() is extern, because it was automatically called from the NMI trap handler. This chunk depends on my fixes for ddb entrance on broadcast NMI and thus not included.
If this is something worth it as interim, please review. If not, I will revert this in my repo to avoid future conflict handling.