stable/8 build broken on head without WITH_CTF

stable/8 build seems to be broken for me on head without WITH_CTF:
...
cc -c -x assembler-with-cpp -DLOCORE -O2 -fno-strict-aliasing -pipe -march=k8
-std=c99 -g -O -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef
-Wno-pointer-sign -fformat-extensions -nostdinc  -I.
-I/usr/devel/svn/base/stable/8/sys
-I/usr/devel/svn/base/stable/8/sys/contrib/altq -D_KERNEL
-DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h -fno-common
-finline-limit=8000 --param inline-unit-growth=100 --param
large-function-growth=1000  -fno-omit-frame-pointer -mcmodel=kernel
-mno-red-zone  -mfpmath=387 -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow
-msoft-float -fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
-Werror /usr/devel/svn/base/stable/8/sys/amd64/amd64/locore.S
: No such file or directory
*** Error code 1

The reason is that kernel Makefile (generated by config I assume) has these in
it (just two examples):
...
cam.o: $S/cam/cam.c
        ${NORMAL_C}
        _at_${NORMAL_CTFCONVERT}
...
locore.o: $S/amd64/amd64/locore.S
        ${NORMAL_S}
        _at_${NORMAL_CTFCONVERT}
...

The issue is that NORMAL_CTFCONVERT has an empty value unless WITH_CTF is used,
see sys/conf/kern.pre.mk of stable/8.
I guess this happens because config is from head, but mk files are from stable/8.

If we don't try to support such build configurations, then sorry for the noise.
But if this can be made to work without much hassle, then I'd appreciate it.
Thanks!

-- 
Andriy Gapon