Report warning on unresolved unqualified access.

sdk/lib/_internal/compiler/implementation/typechecker.dart

Index: sdk/lib/_internal/compiler/implementation/typechecker.dart
diff --git a/sdk/lib/_internal/compiler/implementation/typechecker.dart b/sdk/lib/_internal/compiler/implementation/typechecker.dart
index 856eaa5f9d713770a0488d7a596d959ce161040c..49612a981971842342a9d69edd45c6157209ef70 100644
--- a/sdk/lib/_internal/compiler/implementation/typechecker.dart
+++ b/sdk/lib/_internal/compiler/implementation/typechecker.dart
@@ -550,8 +550,12 @@ class TypeCheckerVisitor extends Visitor<DartType> {
    */
   ElementAccess computeResolvedAccess(Send node, SourceString name,
                                       Element element, MemberKind memberKind) {
-    if (Elements.isUnresolved(element)) {
+    if (element == null) {
       // foo() where foo is unresolved.
+      return lookupMember(node, currentClass.computeType(compiler),
+          name, memberKind);
+    } else if (element.isErroneous()) {
+      // foo() where foo is erroneous.
       return const DynamicAccess();
     } else if (element.isMember()) {
       // foo() where foo is an instance member.