Remove irange::{min,max,kind}.

Remove irange::{min,max,kind}.

gcc/ChangeLog:

	* tree-ssa-loop-niter.cc (refine_value_range_using_guard): Remove
	kind() call.
	(determine_value_range): Same.
	(record_nonwrapping_iv): Same.
	(infer_loop_bounds_from_signedness): Same.
	(scev_var_range_cant_overflow): Same.
	* tree-vrp.cc (operand_less_p): Delete.
	* tree-vrp.h (operand_less_p): Delete.
	* value-range.cc (get_legacy_range): Remove uses of deprecated API.
	(irange::value_inside_range): Delete.
	* value-range.h (vrange::kind): Delete.
	(irange::num_pairs): Remove check of m_kind.
	(irange::min): Delete.
	(irange::max): Delete.