Refactoring resolution of local access and unqualified access of statics

pkg/compiler/lib/src/enqueue.dart

Index: pkg/compiler/lib/src/enqueue.dart
diff --git a/pkg/compiler/lib/src/enqueue.dart b/pkg/compiler/lib/src/enqueue.dart
index 186025c052e08890ebc8a11087611413840fb6a8..3d2bb00b7c8eec5cfe8714718db6efcd9e6cea79 100644
--- a/pkg/compiler/lib/src/enqueue.dart
+++ b/pkg/compiler/lib/src/enqueue.dart
@@ -546,7 +546,8 @@ abstract class Enqueuer {
    */
   void registerStaticUse(Element element) {
     if (element == null) return;
-    assert(invariant(element, element.isDeclaration));
+    assert(invariant(element, element.isDeclaration,
+        message: "Element ${element} is not the declaration."));
     if (Elements.isStaticOrTopLevel(element) && element.isField) {
       universe.registerStaticFieldUse(element);
     }