Change memberName and namedArguments in Invocation to use Symbol.

dart/tests/language/super_operator_index7_test.dart

Index: dart/tests/language/super_operator_index7_test.dart
diff --git a/dart/tests/language/super_operator_index7_test.dart b/dart/tests/language/super_operator_index7_test.dart
index fb0b78ae537ac06e11e93a843a7b2c4bd63adc2b..261163ddcc7ee7620a0f755ef52b5c11d734c0b6 100644
--- a/dart/tests/language/super_operator_index7_test.dart
+++ b/dart/tests/language/super_operator_index7_test.dart
@@ -10,10 +10,10 @@ class A {
   var indexField = new List(2);
 
   noSuchMethod(Invocation im) {
-    if (im.memberName == '[]=') {
+    if (im.memberName == const Symbol('[]=')) {
       Expect.equals(2, im.positionalArguments.length);
       indexField[im.positionalArguments[0]] = im.positionalArguments[1];
-    } else if (im.memberName == '[]') {
+    } else if (im.memberName == const Symbol('[]')) {
       Expect.equals(1, im.positionalArguments.length);
       return indexField[im.positionalArguments[0]];
     } else {