Handle static fields in js_model/model_test

tests/compiler/dart2js/js_model/model_test.dart

Index: tests/compiler/dart2js/js_model/model_test.dart
diff --git a/tests/compiler/dart2js/js_model/model_test.dart b/tests/compiler/dart2js/js_model/model_test.dart
index fe829f09a8425b7b0e34d7972935acd42f433c76..d1bed70961a16c2f5145d42f7ffbcef6f034a249 100644
--- a/tests/compiler/dart2js/js_model/model_test.dart
+++ b/tests/compiler/dart2js/js_model/model_test.dart
@@ -19,6 +19,7 @@ foo({named}) => 1;
 bar(a) => !a;
 class Class {
   var field;
+  static var staticField;
 
   Class();
   Class.named(this.field);
@@ -40,6 +41,14 @@ main() {
   new Object();
   new Class.named('');
   new SubClass().method();
+  Class.staticField;
+  var x = null;
+  var y1 = x == null;
+  var y2 = null == x;
+  var z1 = x?.toString();
+  var z2 = x ?? y1;
+  var z3 = x ??= y2;
+  return x;
 }
 '''
 };