gimple-ssa-evrp.c (class evrp_range_analyzer): New class extracted from evrp_dom_walker class.

	* gimple-ssa-evrp.c (class evrp_range_analyzer): New class extracted
	from evrp_dom_walker class.  Various methods moved into new class.
	(evrp_range_analyzer::evrp_range_analyzer): Constructor for new class.
	(evrp_range_analyzer::enter): New method.
	(evrp_range_analyzer::leave): New method.
	(evrp_dom_walker): Remove delegators no longer needed by this class.
	Replace vr_values data member with evrp_range_analyzer

From-SVN: r254884