r 307698: buildworld failure: tconfig.h:6:10: fatal error: 'auto-host.h' file not found

Recent r307698 is preventued from beeing built by a compiler error, see below.

I also face a problem with the subversion tree a couple of day right now:

 # svn update
Updating '.':
Restored 'tests/sys/geom/class/uzip/1_endian_little.img.uzip.uue'
At revision 307698.

This 'restored' message occurs all the time until I emmit a restore command in
svn.

Kind regards,

oh

[...]
cc -target x86_64-unknown-freebsd12.0 --sysroot=/usr/obj/usr/src/tmp
-B/usr/obj/usr/src/tmp/usr/bin -c -O2 -pipe -O3 -O3 -march=native  -DIN_GCC
-DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED  -DHAVE_GTHR_DEFAULT
-I/usr/src/gnu/lib/libgcc/../../../contrib/gcclibs/include
-I/usr/src/gnu/lib/libgcc/../../../contrib/gcc/config
-I/usr/src/gnu/lib/libgcc/../../../contrib/gcc -I.
-I/usr/src/gnu/lib/libgcc/../../../contrib/llvm/projects/libunwind/include
-I/usr/src/gnu/lib/libgcc -D_LIBUNWIND_IS_NATIVE_ONLY -DNDEBUG -std=gnu99
-Qunused-arguments   -fpic -DSHARED  -DL_enable_execute_stack -o
_enable_execute_stack.pico /usr/src/gnu/lib/libgcc/../../../contrib/gcc/libgcc2.c
--- _negdi2.pico --- In file included
from /usr/src/gnu/lib/libgcc/../../../contrib/gcc/libgcc2.c:32: ---
_muldi3.pico --- In file included
from /usr/src/gnu/lib/libgcc/../../../contrib/gcc/libgcc2.c:32: ./tconfig.h:6:10:
fatal error: 'auto-host.h' file not found #include "auto-host.h"