Change fast VRP algorithm

Change fast VRP algorithm

Change the fast VRP algorithm to track contextual ranges active within
each basic block.

	* gimple-range.cc (dom_ranger::dom_ranger): Create a block
	vector.
	(dom_ranger::~dom_ranger): Dispose of the block vector.
	(dom_ranger::edge_range): Delete.
	(dom_ranger::range_on_edge): Combine range in src BB with any
	range gori_nme_on_edge returns.
	(dom_ranger::range_in_bb): Combine global range with any active
	contextual range for an ssa-name.
	(dom_ranger::range_of_stmt): Fix non-ssa LHS case, use
	fur_depend for folding so relations can be registered.
	(dom_ranger::maybe_push_edge): Delete.
	(dom_ranger::pre_bb): Create incoming contextual range vector.
	(dom_ranger::post_bb): Free contextual range vector.
	* gimple-range.h (dom_ranger::edge_range): Delete.
	(dom_ranger::m_e0): Delete.
	(dom_ranger::m_e1): Delete.
	(dom_ranger::m_bb): New.
	(dom_ranger::m_pop_list): Delete.
	* tree-vrp.cc (execute_fast_vrp): Enable relation oracle.