perf(map): use Array.prototype.map

Replace helper functions with the native ES5 method

src/Angular.js

@@ -50,7 +50,6 @@
   trim: true,
   isElement: true,
   makeMap: true,
-  map: true,
   size: true,
   includes: true,
   arrayRemove: true,
@@ -617,15 +616,6 @@ function nodeName_(element) {
 }
 
 
-function map(obj, iterator, context) {
-  var results = [];
-  forEach(obj, function(value, index, list) {
-    results.push(iterator.call(context, value, index, list));
-  });
-  return results;
-}
-
-
 /**
  * @description
  * Determines the number of elements in an array, the number of properties an object has, or