fix(change-detector): handle double.NAN for collections (in JS)

lib/change_detection/dirty_checking_change_detector.dart

@@ -793,11 +793,17 @@ class _CollectionChangeRecord<V> implements CollectionChangeRecord<V> {
    */
   ItemRecord mismatch(ItemRecord record, item, int index) {
     // Guard against bogus String changes
-    if (record != null && item is String && record.item is String &&
-        record.item == item) {
-      // this is false change in strings we need to recover, and pretend it is
-      // the same. We save the value so that next time identity will pass
-      return record..item = item;
+    if (record != null) {
+      if (item is String && record.item is String && record.item == item) {
+        // this is false change in strings we need to recover, and pretend it is
+        // the same. We save the value so that next time identity can pass
+        return record..item = item;
+      }
+
+      if (item is num && item.isNaN && record.item is num && record.item.isNaN){
+        // we need this for JavaScript since in JS NaN !== NaN.
+        return record;
+      }
     }
 
     // find the previous record so that we know where to insert after.

test/change_detection/dirty_checking_change_detector_spec.dart

@@ -245,14 +245,20 @@ main() => describe('DirtyCheckingChangeDetector', () {
 
     it('should test string by value rather than by reference', () {
       var list = ['a', 'boo'];
-      var record = detector.watch(list, null, 'handler');
-      detector.collectChanges();
+      detector..watch(list, null, null)..collectChanges();
 
       list[1] = 'b' + 'oo';
 
       expect(detector.collectChanges()).toEqual(null);
     });
 
+    it('should ignore [NaN] != [NaN]', () {
+      var list = [double.NAN];
+      var record = detector..watch(list, null, null)..collectChanges();
+
+      expect(detector.collectChanges()).toEqual(null);
+    });
+
     it('should remove and add same item', () {
       var list = ['a', 'b', 'c'];
       var record = detector.watch(list, null, 'handler');