rename widest_irange to int_range_max.

rename widest_irange to int_range_max.

gcc/ChangeLog:

	* range-op.cc (range_operator::fold_range): Rename widest_irange
	to int_range_max.
	(operator_div::wi_fold): Same.
	(operator_lshift::op1_range): Same.
	(operator_rshift::op1_range): Same.
	(operator_cast::fold_range): Same.
	(operator_cast::op1_range): Same.
	(operator_bitwise_and::remove_impossible_ranges): Same.
	(operator_bitwise_and::op1_range): Same.
	(operator_abs::op1_range): Same.
	(range_cast): Same.
	(widest_irange_tests): Same.
	(range3_tests): Rename irange3 to int_range3.
	(int_range_max_tests): Rename from widest_irange_tests.
	Rename widest_irange to int_range_max.
	(operator_tests): Rename widest_irange to int_range_max.
	(range_tests): Same.
	* tree-vrp.c (find_case_label_range): Same.
	* value-range.cc (irange::irange_intersect): Same.
	(irange::invert): Same.
	* value-range.h: Same.