Task: Build Type Aliases.

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 7a6952e790e3a761b1db1b16abd61aa0f19d5050..ba52cc61eeeef7e99500084782d4ed5c6a0ae3b9 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -9460,6 +9460,14 @@ class NamespaceBuilder {
    */
   HashMap<String, Element> _createExportMapping(
       LibraryElement library, HashSet<LibraryElement> visitedElements) {
+    // Check if the export namespace has been already computed.
+    {
+      Namespace exportNamespace = library.exportNamespace;
+      if (exportNamespace != null) {
+        return exportNamespace.definedNames;
+      }
+    }
+    // TODO(scheglov) Remove this after switching to the new task model.
     visitedElements.add(library);
     try {
       HashMap<String, Element> definedNames = new HashMap<String, Element>();