refactor(injector): change reflector to collect the resolving path only when an error occurs

modules/facade/src/collection.dart

@@ -24,9 +24,15 @@ class ListWrapper {
   static forEach(list, fn) {
     list.forEach(fn);
   }
-  static last(list) {
+  static first(List list) {
+    return list.first;
+  }
+  static last(List list) {
     return list.last;
   }
+  static reversed(List list) {
+    return list.reversed;
+  }
   static void push(List l, e) { l.add(e); }
 }
 

modules/facade/src/collection.es6

@@ -34,10 +34,18 @@ export class ListWrapper {
   static push(array, el) {
     array.push(el);
   }
+  static first(array) {
+    if (!array) return null;
+    return array[0];
+  }
   static last(array) {
     if (!array || array.length == 0) return null;
     return array[array.length - 1];
   }
+  static reversed(array) {
+    var a = ListWrapper.clone(array);
+    return a.reverse();
+  }
 }
 
 export class SetWrapper {