Fix for navigation reginos for instance creations with import prefixes.

pkg/analysis_server/test/analysis/notification_navigation_test.dart

Index: pkg/analysis_server/test/analysis/notification_navigation_test.dart
diff --git a/pkg/analysis_server/test/analysis/notification_navigation_test.dart b/pkg/analysis_server/test/analysis/notification_navigation_test.dart
index e0ed9888d00b39f75baa07e9e33a10e3a8c9d090..2e56daa1e845b08d270c744256a3c7f4195e9033 100644
--- a/pkg/analysis_server/test/analysis/notification_navigation_test.dart
+++ b/pkg/analysis_server/test/analysis/notification_navigation_test.dart
@@ -672,6 +672,22 @@ main() {
     }
   }
 
+  test_instanceCreation_withImportPrefix_named() async {
+    addTestFile('''
+import 'dart:async' as ppp;
+main() {
+  new ppp.Future.value(42);
+}
+''');
+    await prepareNavigation();
+    {
+      assertHasRegion('ppp.');
+      assertHasTarget('ppp;');
+    }
+    assertHasRegion('Future.value');
+    assertHasRegion('value(42)');
+  }
+
   test_library() async {
     addTestFile('''
 library my.lib;