Reinstall previous behavior for Set and Queue toString.

tests/compiler/dart2js/mirrors_used_test.dart

Index: tests/compiler/dart2js/mirrors_used_test.dart
diff --git a/tests/compiler/dart2js/mirrors_used_test.dart b/tests/compiler/dart2js/mirrors_used_test.dart
index ce0df8b9139634cd059e327a7a2f2719f01087be..4f788409e8059aaadb563412eebbcd0b97f1ffbe 100644
--- a/tests/compiler/dart2js/mirrors_used_test.dart
+++ b/tests/compiler/dart2js/mirrors_used_test.dart
@@ -59,7 +59,7 @@ void main() {
     // 2. Some code was refactored, and there are more methods.
     // Either situation could be problematic, but in situation 2, it is often
     // acceptable to increase [expectedMethodCount] a little.
-    int expectedMethodCount = 382;
+    int expectedMethodCount = 380;
     Expect.isTrue(
         generatedCode.length <= expectedMethodCount,
         'Too many compiled methods: '