suggest loadLibrary is import is deferred

pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart

Index: pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
diff --git a/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart b/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
index 85af87994fa665db38fe83e488bf9d2b82ac0169..790d1ca208272d308e9bb219ff5e8d6bf0c4b5f5 100644
--- a/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
+++ b/pkg/analysis_server/test/services/completion/prefixed_element_contributor_test.dart
@@ -142,6 +142,7 @@ void f(C<int> c) {
     addTestSource('import "dart:async" as bar; foo() {bar.^}');
     return computeFull((bool result) {
       assertSuggestClass('Future');
+      assertNotSuggested('loadLibrary');
     });
   }
 
@@ -153,6 +154,15 @@ void f(C<int> c) {
     });
   }
 
+  test_libraryPrefix_deferred() {
+    // SimpleIdentifier  PrefixedIdentifier  ExpressionStatement
+    addTestSource('import "dart:async" deferred as bar; foo() {bar.^}');
+    return computeFull((bool result) {
+      assertSuggestClass('Future');
+      assertSuggestFunction('loadLibrary', 'void');
+    });
+  }
+
   test_local() {
     addTestSource('foo() {String x = "bar"; x.^}');
     return computeFull((bool result) {