acpi_einj: Support for ACPI error injection

[jhb]

Summary

This driver parses the ACPI EINJ table and builds a list of
instructions associated with known actions. It then exports ioctls to
fetch the set of supported errors and inject system errors by
executing specific sequences of actions. This can be used to test
error reporting facilities for events such as ECC errors.

Sponsored by: Netflix

[jhb]

Fix order of operands to copyout for the vendor structure and add apei_if.h
to the module Makefile (noted by Claude)

[gallatin]

sys/dev/acpica/acpi_einj.c

150

Would be nice to have more data about the expected vs actual data in all these cases. Should be harmless to be chatty, since its under bootverbose, and might reduce round-trips when triaging issues with this.

[jhb]

sys/dev/acpica/acpi_einj.c

150

Hmm, for many of these I didn't bother since acpidump -t already outputs these details so you can figure out what didn't match from the dump. It doesn't hurt to be more chatty though.