Vector ILookup and IFn issues

- -lookup needs to use nil so it doesn't throw
- -invoke should not take extra parameter, just copy PersistentVector
  implementation
- clojure.data-test passing now

Author: swannodette

src/main/cljs/cljs/core.cljs

@@ -12372,7 +12372,7 @@ reduces them without incurring seq initialization"
   ILookup
   (-lookup [coll k]
     (when (number? k)
-      (-nth coll k)))
+      (-nth coll k nil)))
   (-lookup [coll k not-found]
     (if (number? k)
       (-nth coll k not-found)
@@ -12424,9 +12424,9 @@ reduces them without incurring seq initialization"
 
   IFn
   (-invoke [coll k]
-    (-lookup coll k))
-  (-invoke [coll k not-found]
-    (-lookup coll k not-found))
+    (if (number? k)
+      (-nth coll k)
+      (throw (js/Error. "Key must be integer"))))
 
   IEditableCollection
   (-as-transient [coll]

src/test/cljs/lite_test_runner.cljs

@@ -87,7 +87,7 @@
   'cljs.ns-test
   'clojure.set-test
   'clojure.string-test
-  #_'clojure.data-test ;; 1 failure #object[Error Error: No item 1 in vector of length 1]
+  'clojure.data-test
   'clojure.datafy-test
   'clojure.edn-test
   'clojure.walk-test