Avoid "Member not found exception" in IE10

'change' custom events raise "Member not found" in <= IE10. To
circumvent this, the SyntheticEvent class now checks for "typeof
event.cancelBubble !== 'unknown'". This eliminates this exception and
maintains the expected bubbling functionality.

Addresses facebook#7320.

src/renderers/dom/client/syntheticEvents/SyntheticEvent.js

@@ -135,9 +135,15 @@ Object.assign(SyntheticEvent.prototype, {
 
     if (event.stopPropagation) {
       event.stopPropagation();
-    } else {
+    } else if (typeof event.cancelBubble !== 'unknown') { // eslint-disable-next-line valid-typeof
+      // The ChangeEventPlugin registers a "propertychange" event for
+      // IE. This event does not support bubbling or cancelling, and
+      // any references to cancelBubble throw "Member not found".  A
+      // typeof check of "unknown" circumvents this issue (and is also
+      // IE specific).
       event.cancelBubble = true;
     }
+
     this.isPropagationStopped = emptyFunction.thatReturnsTrue;
   },