Add relational support to fold_using_range

Add relational support to fold_using_range

Enable a relation oracle in ranger, and add full range-op relation support
to fold_using_range.

	* gimple-range-cache.cc (ranger_cache::ranger_cache): Create a
	relation_oracle if dominators exist.
	(ranger_cache::~ranger_cache): Dispose of oracle.
	(ranger_cache::dump_bb): Dump oracle.
	* gimple-range.cc (fur_source::fur_source): New.
	(fur_source::get_operand): Use mmeber query.
	(fur_source::get_phi_operand): Use member_query.
	(fur_source::query_relation): New.
	(fur_source::register_dependency): Delete.
	(fur_source::register_relation): New.
	(fur_edge::fur_edge): Adjust.
	(fur_edge::get_phi_operand): Fix comment.
	(fur_edge::query): Delete.
	(fur_stmt::fur_stmt): Adjust.
	(fur_stmt::query): Delete.
	(fur_depend::fur_depend): Adjust.
	(fur_depend::register_relation): New.
	(fur_depend::register_relation): New.
	(fur_list::fur_list): Adjust.
	(fur_list::get_operand): Use member query.
	(fold_using_range::range_of_range_op): Process and query relations.
	(fold_using_range::range_of_address): Adjust dependency call.
	(fold_using_range::range_of_phi): Ditto.
	(gimple_ranger::gimple_ranger): New.  Use ranger_ache oracle.
	(fold_using_range::relation_fold_and_or): New.
	(fold_using_range::postfold_gcond_edges): New.
	* gimple-range.h (class gimple_ranger): Adjust.
	(class fur_source): Adjust members.
	(class fur_stmt): Ditto.
	(class fold_using_range): Ditto.