[PATCH] kernelbase: Avoid NULL-pointer dereferences.

[Gen Otsuji]

Hi,
Sorry for inconvenience, this patch is very nice, and resolve this
trapno difference, I think.
the URL is,
https://github.com/shkhln/freebsd-lib32-companion-ports/blob/1aff798add915fcb787627aa50a63240bde2b5ac/emulators/wine-devel/files/patch-dlls_ntdll_signal_x86_64.c
from https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=246426#c6

Cheers
Gen Otsuji