CLJ-2247: restore last match semantics of {min,max}-key

The CLJ-99 patch (d10a9d3) makes two
changes to the behaviour of {min,max}-key:

 1. it ensures that the key function is only called once on each
    argument;

 2. it causes both functions to return the first match, whereas
    previously they returned the last one.

This preserves 1. and reverts 2.

Signed-off-by: Stuart Halloway <stu@cognitect.com>

Author: michalmarczyk

src/clj/clojure/core.clj

@@ -4944,7 +4944,7 @@
        (if more
          (let [w (first more)
                kw (k w)]
-           (if (> kw kv)
+           (if (>= kw kv)
              (recur w kw (next more))
              (recur v kv (next more))))
          v)))))
@@ -4962,7 +4962,7 @@
        (if more
          (let [w (first more)
                kw (k w)]
-           (if (< kw kv)
+           (if (<= kw kv)
              (recur w kw (next more))
              (recur v kv (next more))))
          v)))))

test/clojure/test_clojure/other_functions.clj

@@ -335,7 +335,10 @@
        count ["longest" "a" "xy" "foo" "bar"] "a" "longest"
        - [5 10 15 20 25] 25 5
        #(if (neg? %) (- %) %) [-2 -1 0 1 2 3 4] 0 4
-       {nil 1 false -1 true 0} [true true false nil] false nil))
+       {nil 1 false -1 true 0} [true true false nil] false nil)
+  (are [f k coll expected] (= expected (apply f k coll))
+    min-key :x [{:x 1000} {:x 1001} {:x 1002} {:x 1000 :second true}] {:x 1000 :second true}
+    max-key :x [{:x 1000} {:x 999} {:x 998} {:x 1000 :second true}] {:x 1000 :second true}))
 
 
 ; Printing