This fixes a GDB crash observed on Android 8.0 when GDB was
cross-compiled. This patch is a backport of a patch pushed
upstream in gnulib.

gdb/ChangeLog (Sergio Durigan Junior  <sergiodj@redhat.com>):

        PR gdb/23558
        * gnulib/import/m4/getcwd-path-max.m4: Add handling of Hurd,
        Linux and kFreeBSD platforms.
        * gnulib/configure: Regenerate.