Update an out-of-date test.

tests/compiler/dart2js/dart_backend_test.dart

Index: tests/compiler/dart2js/dart_backend_test.dart
diff --git a/tests/compiler/dart2js/dart_backend_test.dart b/tests/compiler/dart2js/dart_backend_test.dart
index 9e525999842b5ace60f53d230463afe6feacb0c2..6f71990c1119be85ab2888362d098cd3ef940e72 100644
--- a/tests/compiler/dart2js/dart_backend_test.dart
+++ b/tests/compiler/dart2js/dart_backend_test.dart
@@ -387,7 +387,7 @@ main() {
     'class A{foo(){}}'
     'A_topfoo(){var x=5;}'
     'class A_A{num foo(){}A_A.fromFoo(){}A myliba;List<A_A> mylist;}'
-    'A getA()=>null;'
+    'A getA(){}'
     'main(){var a=new A();a.foo();var b=new A_A.fromFoo();b.foo();'
         'var GREATVAR=b.myliba;b.mylist;a=getA();A_topfoo();topfoo();}';
   testDart2DartWithLibrary(mainSrc, librarySrc,