fix equiv-map typo, make public, clarify docstring

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -5828,24 +5828,24 @@ reduces them without incurring seq initialization"
 
 (def ^:private never-equiv (NeverEquiv.))
 
-(defn- ^boolean equiv-map
-  "Assumes y is a map. Returns true if x equals y, otherwise returns
-  false."
+(defn ^boolean equiv-map
+  "Test map equivalence. Returns true if x equals y, otherwise returns false."
   [x y]
   (boolean
     (when (and (map? y) (not (record? y)))
       ; assume all maps are counted
       (when (== (count x) (count y))
         (if (satisfies? IKVReduce x)
-          (reduce-kv (fn [_ k v]
-                       (if (= (get y k never-equiv) v)
-                         true
-                         (reduced false)))
-                     true
-                     x)
-          (every? (fn [xkv] (= (get y (first xkv) never-equiv)
-                               (second v)))
-                  x))))))
+          (reduce-kv
+            (fn [_ k v]
+              (if (= (get y k never-equiv) v)
+                true
+                (reduced false)))
+            true x)
+          (every?
+            (fn [xkv]
+              (= (get y (first xkv) never-equiv) (second xkv)))
+            x))))))
 
 
 (defn- scan-array [incr k array]