bug#58535: Build failure on old GNU/Linux system

[Po Lu]

Since the last gnulib merge, I've been getting

make -C lib all
  CC       fingerprint.o
make[1]: Entering directory `/home/oldosfan/emacs/lib'
In file included from ../src/config.h:2877,
                 from fingerprint.c:20:
../src/conf_post.h:61: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ 
before ‘bool_bf’
make[1]: *** [fingerprint.o] Error 1

on an old GNU/Linux system (Fedora 12).  Paul, could you please fix
this?  Thanks in advance.