Saturate overflows return from SCEV in ranger.

Saturate overflows return from SCEV in ranger.

bounds_of_var_in_loop is returning an overflowed int, which is causing
us to create a range for which we can't compare the bounds causing
an ICE in verify_range.

Overflowed bounds cause compare_values() to return -2, which we
don't handle in verify_range.

We don't represent overflowed ranges in irange, so this patch just
saturates any overflowed end-points to MIN or MAX.

gcc/ChangeLog:

	PR tree-optimization/97501
	* gimple-range.cc (gimple_ranger::range_of_ssa_name_with_loop_info):
	Saturate overflows returned from SCEV.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr97501.c: New test.