Merge CommonElements and BackendHelpers!

pkg/compiler/lib/src/ssa/graph_builder.dart

Index: pkg/compiler/lib/src/ssa/graph_builder.dart
diff --git a/pkg/compiler/lib/src/ssa/graph_builder.dart b/pkg/compiler/lib/src/ssa/graph_builder.dart
index 12f1482481a2f364a52c235432eec30dcdfd2cd8..ab94bc48e0ae2589e7d91c9b2ae13d55f27174e3 100644
--- a/pkg/compiler/lib/src/ssa/graph_builder.dart
+++ b/pkg/compiler/lib/src/ssa/graph_builder.dart
@@ -11,7 +11,6 @@ import '../diagnostics/diagnostic_listener.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart' show Entity, Local;
 import '../elements/resolution_types.dart';
-import '../js_backend/backend_helpers.dart';
 import '../js_backend/backend_usage.dart';
 import '../js_backend/constant_handler_javascript.dart';
 import '../js_backend/js_backend.dart';
@@ -85,8 +84,6 @@ abstract class GraphBuilder {
 
   ConstantSystem get constantSystem => constants.constantSystem;
 
-  BackendHelpers get helpers => backend.helpers;
-
   RuntimeTypesEncoder get rtiEncoder => backend.rtiEncoder;
 
   FunctionInlineCache get inlineCache => backend.inlineCache;