Update repo to use dart2js from pkg/compiler.

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 6457d26c5d7ebaa1b55080a392a9a753f6cc9176..611dd9863eca6fc265daac6cf8d0aa0814fb3ba6 100644
--- a/tests/compiler/dart2js/mirrors_used_test.dart
+++ b/tests/compiler/dart2js/mirrors_used_test.dart
@@ -12,18 +12,18 @@ import "package:async_helper/async_helper.dart";
 import 'memory_compiler.dart' show
     compilerFor;
 
-import 'package:compiler/implementation/apiimpl.dart' show
+import 'package:compiler/src/apiimpl.dart' show
     Compiler;
 
-import 'package:compiler/implementation/constants/values.dart' show
+import 'package:compiler/src/constants/values.dart' show
     ConstantValue,
     TypeConstantValue;
 
-import 'package:compiler/implementation/elements/elements.dart' show
+import 'package:compiler/src/elements/elements.dart' show
     Element,
     Elements;
 
-import 'package:compiler/implementation/js_backend/js_backend.dart' show
+import 'package:compiler/src/js_backend/js_backend.dart' show
     JavaScriptBackend;
 
 void expectOnlyVerboseInfo(Uri uri, int begin, int end, String message, kind) {