complied and basic testing by now:
commands needed to compile
LDFLAGS=-static ./configure --host i686-w64-mingw32 --disable-nls LDFLAGS=-static make -j 9
commands needed for debugging
wine src/diff.exe src/util.c ../diffutils-3.6-org/src/util.c -u i686-w64-mingw32-addr2line -e src/diff.exe 0x00012fa7
created a diff in case someone needs it
diff -r ../diffutils-3.6-org ./ -u > ../diffutils-3.6-winbuild.patci686-w64-mingw32 binarys