Remove range_int_cst_p.

Remove range_int_cst_p.

gcc/ChangeLog:

	* tree-data-ref.cc (compute_distributive_range): Replace uses of
	range_int_cst_p with irange API.
	* tree-ssa-strlen.cc (get_range_strlen_dynamic): Same.
	* tree-vrp.h (range_int_cst_p): Delete.
	* vr-values.cc (check_for_binary_op_overflow): Replace usees of
	range_int_cst_p with irange API.
	(vr_set_zero_nonzero_bits): Same.
	(range_fits_type_p): Same.
	(simplify_using_ranges::simplify_casted_cond): Same.
	* tree-vrp.cc (range_int_cst_p): Remove.