glob: port to clang's Undefined Sanitizer Problem reported by Tim Rühsen in: http://lists.gnu.org/archive/html/bug-gnulib/2017-08/msg00144.html * lib/glob.c (FLEXIBLE_ARRAY_MEMBER) [_LIBC]: Define to empty. (glob_in_dir): Do not rely on undefined behavior in accessing struct members beyond their bounds. Use a flexible array member instead.