Starting NPF crashes amd64 -current (23 Jan 2017)

[Geoff Wing <gcw%pobox.com@localhost>]

Hi,
starting -current on amd64, I get a crash during (presumably) /etc/rc.d/npf

I have some dynamic tables in /etc/npf.conf, e.g.
	table <limited> type tree dynamic
though maybe not relevant.

Panics are copied from phone video.  I can't get a crash dump, nor
does my computer keep system message logs over reboot.

One panic had
--------------------
panic: kernel diagnostic assertion "elements > 0" filed: sys/kern/subr_hash.c: line 93

vpanic()
ch_voltag_convert_in()
hashinit()+0x1b4
npf_table_create()+0xc7
pf_mk_tables.isra.0()+0x20f
npfctl_load()+0x1d3
VOP_IOCTL()
vn_ioctl()
sys_ioctl()
syscal()
-- syscall (54)
dumping to dev 168,10 .... not possible
rebooting
--------------------

After several rebuilds and changing dump device, I get

db{0}> sync

dumping to dev 168,10 (offset=27281471, size=3143454)
dump uvm_fault(0xfffffe833bacd5c8, 0x0, 1) -> e
fatal page fault in supervisor mode
trap type 6
...blah...
Stopped in pid 206.1 (npfctl) at 	netbsd:sparse_dump_mark+0x10c: cmpq $0,38(%rax)