PR middle-end/17894
	* fold-const.c (fold_div_compare): When optimizing X/C1 op C2, the
	relational comparison operator op needs to be swapped/reversed when
	C1 is negative.  i.e. X/-10 < 1 becomes X >= -9, not X < -9.

	* gcc.c-torture/execute/divcmp-4.c: New test case.

From-SVN: r88818