Make hasNext a getter instead of a method.

runtime/lib/array.dart

Index: runtime/lib/array.dart
diff --git a/runtime/lib/array.dart b/runtime/lib/array.dart
index 3a2ca485d551e1d886f26de2768de933dd0e938f..540e4fdf67f2db61d9e370dd43e6642f3be7bf61 100644
--- a/runtime/lib/array.dart
+++ b/runtime/lib/array.dart
@@ -298,12 +298,12 @@ class _FixedSizeArrayIterator<E> implements Iterator<E> {
     assert(array is _ObjectArray || array is _ImmutableArray);
   }
 
-  bool hasNext() {
+  bool get hasNext {
     return _length > _pos;
   }
 
   E next() {
-    if (!hasNext()) {
+    if (!hasNext) {
       throw const NoMoreElementsException();
     }
     return _array[_pos++];