The split/filter.sh test would fail like this:

  $ make check TESTS=tests/split/filter.sh VERBOSE=yes SUBDIRS=.
  + truncate -s9223372036854775807 zero.in
  + timeout 10 sh -c 'split --filter="head -c1 >/dev/null" -n 1 zero.in'
  split: zero.in: cannot determine file size: Value too large for
defined data type

That value is 2^63-1 (nearly 8 exabytes), and split.c
explicitly handles a file of that size, because that is
the size reported for /dev/zero on GNU/Hurd systems,
according to the comment.

This fixes the test not to trigger that work-around:
[I'll update the commit log with the issue URL as soon as it's assigned]