Track value_relations in GORI.

Track value_relations in GORI.

This allows GORI to recognize and pass relations along the calculation chain.
This will allow relations between the LHS and the operand being calculated
to be utilized in op1_range and op2_range.

	* gimple-range-gori.cc (ori_compute::compute_operand_range):
	Create a relation record and pass it along when possible.
	(gori_compute::compute_operand1_range): Pass relation along.
	(gori_compute::compute_operand2_range): Ditto.
	(gori_compute::compute_operand1_and_operand2_range): Ditto.
	* gimple-range-gori.h (class gori_compute): Adjust prototypes.
	* gimple-range-op.cc (gimple_range_op_handler::calc_op1): Pass
	relation to op1_range call.
	(gimple_range_op_handler::calc_op2): Pass relation to op2_range call.
	* gimple-range-op.h (class gimple_range_op_handler): Adjust
	prototypes.