Ensure that the return string is NUL-terminated in acpi_eval_string().

ok jmcneill@, pgoyette@
if_ade doesn't build, suggesting nobody has tried to do anything
else than rototill it for the past n+1 years.  The comments at the
top note a number of clauses after which it can be removed.  I'm
sure that in the past 10+ years those have either been met or become
irrelevant, so remove this.
Introduce acpi_eval_reference_handle() --

an utility function to evaluate reference handles from package elements.

ok jmcneill@, pgoyette@
Add definitions for CAS_INTR_REG and CAS_INTR_PCI.
Fix bpf.  compile-tested only.
Pass correct pointer to bpf_mtap() and most likely avoid a crash
if bpf is activated.

not even compile-tested, since i can't find any config in the tree
which uses this(?)
Use acpi_eval_reference_handle() to simplify code. No functional change.

ok jmcneill@, pgoyette@
Fix and improve several comments.
Remove conditional inclusion of unused bpf.h
nuke unused bpf inclusions
PR/42637: Joachim Kuebart: Shell tab completion crashes due to libedit stack
smashing
Remove unused macro definition (the NetBSD version would just not go
through a compiler).
Add two CTI usb-rs485 adapters
Keep arc4_i and arc4_j synchronised after a rekeying. This prevents
accidentally ending up in a short ARC4 cycle.
regen
Add two CTI rs485 dongles
If no limits are exceeded, make sure we set state to SVALID
Do not check more than 32 bits against ci_feature_flags, to avoid printing
bogus data on /proc/cpuinfo flags line.
Reduce the difference between i386 and amd64 procfs MD code.
Prepare for the merge, no functional changes intended.
Define an empty module_init_md function so that kernels with 'options
MODULAR' can be built (at least in shark).  Still not working due to
some relocations resolving to too far away symbols though.