kern/55736: ipsec_natt and npf tests have regressed on the -9 branch

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         55736
>Category:       kern
>Synopsis:       ipsec_natt and npf tests have regressed on the -9 branch
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Oct 19 18:15:00 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-9; soon to be in 9.1
>Organization:
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

The following test cases are now failing on the -9 branch, tested on
real amd64 hardware.  They did not fail on 9.0.

  net/if_ipsec/t_ipsec_natt:ipsecif_natt_transport_null
  net/if_ipsec/t_ipsec_natt:ipsecif_natt_transport_rijndaelcbc
  net/ipsec/t_ipsec_natt:ipsec_natt_transport_ipv4_null
  net/ipsec/t_ipsec_natt:ipsec_natt_transport_ipv4_rijndaelcbc
  net/npf/t_npf:npf_gc

Logs can be found at:

  http://www.gson.org/netbsd/bugs/build/amd64-9-baremetal/2020/2020.10.16.08.17.09/test.html#failed-tcs-summary

The problems started with one of the pullups to the -9 branch performed
between source dates 2020.06.20.15.46.47 and 2020.06.20.20.03.27.
Auto-bisecting this down to a single pullup failed because of build
breakage.

>How-To-Repeat:

>Fix: