Recent change to fnmatch breaks my build

[Paul J. Lucas]

Hello -

I’ve been using the fnmatch module in Gnulib for a while.  I recently updated 
Gnulib and tried to build and get:

> gcc -DHAVE_CONFIG_H -I. -I../src -g -O2  -Wall -Wcast-align -Wextra 
> -Wredundant-decls -Wwrite-strings -MT fnmatch.o -MD -MP -MF .deps/fnmatch.Tpo 
> -c -o fnmatch.o fnmatch.c
> In file included from fnmatch.c:176:
> ./fnmatch_loop.c:49:41: error: use of undeclared identifier 'FNM_EXTMATCH'
>           if (__builtin_expect (flags & FNM_EXTMATCH, 0) && *p == '(')
>                                         ^

In my project’s lib, there are the files:

        fnmatch.c
        fnmatch.in.h
        fnmatch_loop.c

The fnmatch.h file (that contains the FNM_EXTMATCH symbol) never gets built.

I noticed this recent change to the fnmatch module:

        http://lists.gnu.org/archive/html/bug-gnulib/2018-08/msg00032.html

that seems to have broken the build for me.

For reference, my project is here:

        https://github.com/paul-j-lucas/wrap

In my configure.ac, I have:

        AC_CHECK_HEADERS([fnmatch.h])
        # …
        AC_FUNC_FNMATCH

- Paul