cut: do not print extraneous delimiters in some unusual cases

cut: do not print extraneous delimiters in some unusual cases

When printing output delimiters, and when a to-EOL range subsumes
at least one other range, cut would mistakenly print delimiters for
the subsumed range.  This bug was probably introduced via commit
v5.2.1-639-g847e066.
* src/cut.c (set_fields): Ignore any range that is subsumed by a
to-EOL range.  Also, move two declarations down.
* tests/misc/cut.pl: Add tests to exercise this.
* NEWS (Bug fixes): Mention it.
Reported by Marcel Böhme in http://bugs.gnu.org/12966