bug#7993: cut segmentation fault with unbounded ranges

[Paul Marinescu]

In coreutils 8.9 (latest), the following commands trigger an invalid
memory access.

cut -c1234567890- --output-d=: foo
cut -f1234567890- --output-d=: foo
cut -b1234567890- --output-d=: foo

The number 1234567890 is just a random number 'big enough' to make the
invalid access generate a segmentation fault but the invalid access
happens for values as low as 8 (valgrind)

The problem is that ranges going to end of line (i.e., 'x-') are not
taken into account when calculating the size of the printable_field
vector, but their lower bound is used as an index on line 525:

  if (output_delimiter_specified
      && !complement
      && eol_range_start && !is_printable_field (eol_range_start))


Paul