Issue 21886. Make enums available outside of the defining library.

pkg/analyzer/test/generated/resolver_test.dart

Index: pkg/analyzer/test/generated/resolver_test.dart
diff --git a/pkg/analyzer/test/generated/resolver_test.dart b/pkg/analyzer/test/generated/resolver_test.dart
index 01f5197e463414a08f7262967a789a5ad5d203d2..09669e032e10014f48b258b51c71772cca324806 100644
--- a/pkg/analyzer/test/generated/resolver_test.dart
+++ b/pkg/analyzer/test/generated/resolver_test.dart
@@ -8659,6 +8659,21 @@ main() {}''');
     verify([source]);
   }
 
+  void test_enum_externalLibrary() {
+    resetWithEnum();
+    addNamedSource("/my_lib.dart", r'''
+library my_lib;
+enum EEE {A, B, C}''');
+    Source source = addSource(r'''
+import 'my_lib.dart';
+main() {
+  EEE e = null;
+}''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_extractedMethodAsConstant() {
     Source source = addSource(r'''
 abstract class Comparable<T> {