Use common.dart to re-export commonly used entities.

pkg/compiler/lib/src/js_backend/codegen/glue.dart

Index: pkg/compiler/lib/src/js_backend/codegen/glue.dart
diff --git a/pkg/compiler/lib/src/js_backend/codegen/glue.dart b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
index 7feb21cfd0bec7f27e9adadb1e84caa3fbc81ee6..1c27d48c0f6971985f28aff0e0587f3777dc174e 100644
--- a/pkg/compiler/lib/src/js_backend/codegen/glue.dart
+++ b/pkg/compiler/lib/src/js_backend/codegen/glue.dart
@@ -5,6 +5,8 @@
 library code_generator_dependencies;
 
 import '../js_backend.dart';
+
+import '../../common.dart';
 import '../../common/registry.dart' show
     Registry;
 import '../../common/codegen.dart' show
@@ -16,10 +18,6 @@ import '../../dart_types.dart' show
     DartType,
     TypeVariableType,
     InterfaceType;
-import '../../diagnostics/diagnostic_listener.dart' show
-    DiagnosticReporter;
-import '../../diagnostics/spannable.dart' show
-    CURRENT_ELEMENT_SPANNABLE;
 import '../../enqueue.dart' show
     CodegenEnqueuer;
 import '../../elements/elements.dart';