Update mirrors_used test counter to 432.

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 a96cf2add0c4a91ed04e56f8e09d8da1c0230716..dffab8af88acd6885003a9e98d2c5f07a70efa44 100644
--- a/tests/compiler/dart2js/mirrors_used_test.dart
+++ b/tests/compiler/dart2js/mirrors_used_test.dart
@@ -69,7 +69,7 @@ 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 = 431;
+    int expectedMethodCount = 432;
     Expect.isTrue(
         generatedCode.length <= expectedMethodCount,
         'Too many compiled methods: '