Fixnum#infinite?/Bignum#infinite or Numeric#infinte, consistent with Float#infinite? and BigDecimal#infinite?
We have an issue where it is not easy to ask if a number is +ve or -ve infinity. https://github.com/rails/arel/issues/411
Both Float and BigDecimal do respond to infinite? but Integer derivatives don't. It sort of makes sense, since we don't have an infinity value for Fixnum/Bignum. However, it makes polymorphic code hard.
 pry(main)> Float::INFINITY.infinite? => 1  pry(main)> -Float::INFINITY.infinite? => -1  pry(main)> BigDecimal::INFINITY.infinite? => 1  pry(main)> -BigDecimal::INFINITY.infinite? => -1
Given a Numeric value x, it would be nice to query if it is INFINITY or not. Propose adding a default implementation to Numeric, which always returns false or nil.