POSIX requires that fclose() on seekable input streams rewind back
to the next byte not actually given to the application. Glibc fails
this test. See:
http://sourceware.org/bugzilla/show_bug.cgi?id=3746
http://sourceware.org/bugzilla/show_bug.cgi?id=12724
Likewise for FreeBSD.
Cygwin 1.7.9 and Solaris 10 pass, however.
* modules/fclose-tests: New test module.
* tests/test-fclose.c: New file.