Tests whether one deque is the suffix of another.

The deques must have the same type: two arrays, or two strings, but not an array and a string.

(prn (ends-with? "Hera" "ra")) ; prints #t
(prn (ends-with? "Hera" ""))   ; prints #t
(prn (ends-with? "Hera" "Ra")) ; prints #f