Provide a relation verification mechanism.

Provide a relation oracle API which validates a relation between 2 ranges.
This allows relation queries that are symbolicly true to be overridden
by range specific information.  ie. x == x is true symbolically, but for
floating point a NaN may invalidate this assumption.

	* (relation_to_code): New vector.
	(relation_oracle::validate_relation): New.
	(set_relation): Allow ssa1 == ssa2 to be registered.
	* value-relation.h (validate_relation): New prototype.
	(query_relation): Make internal variant protected.
2 files changed