Initialize vr_values.
	(evrp_range_analyzer::try_find_new_range): Call methods attached to
	vr_values via vr_values class instance rather than delegators.
	(evrp_range_analyzer::record_ranges_from_phis): Likewise.
	(evrp_range_analyzer::record_ranges_from_stmt): Likewise.
	(evrp_range_analyzer::push_value_range): Likewise.
	(evrp_range_analyzer::pop_value_range): Likewise.
	* gimple-ssa-evrp-analyze.h (class evrp_range_analyzer): Remove
	most delegators.  Those remaining are exposed as public interfaces.
	Make vr_values a pointer and private.
	(evrp_range_analyzer::~evrp_range_analyzer): Delete the attached
	vr_values.
	(evrp_range_analyzer::get_vr_value): New method.
	* gimple-ssa-evrp.c (class evrp_folder): Use DISABLE_COPY_AND_ASSIGN.
	(evrp_folder::evrp_folder): New ctor to initialize vr_values.
	(class evrp_dom_walker): Attach evrp_folder class, initialize
	it in the ctor.  Remove temporary delegators.
	(evrp_dom_walker::before_dom_children): Call methods in attached
	evrp_range_analyzer class via class instance pointer.  Use
	free value_range_constant_singleton to remove need for
	op_with_constant_singleton_value delegator method.  Do not
	create a vrp_prop class instance for every call!  Narrow
	scope of a couple variables.
	(evrp_dom_walker::cleanup): Call methods in attached
	evrp_range_analyzer class via class instance pointer.
	* vr-values.h (class vr_values): Privatize many methods and
	data members.

From-SVN: r255074