quick fix for EXTERNAL_ENUM

See: https://github.com/dart-lang/sdk/issues/55917

Change-Id: I0f60078bfcb3ae5ab6d559a9e2314abe209726bf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/369880
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Auto-Submit: Phil Quitslund <pquitslund@google.com>

pkg/analysis_server/lib/src/services/correction/error_fix_status.yaml

@@ -45,8 +45,8 @@
 #
 # Stats:
 # -  42 "needsEvaluation"
-# - 342 "needsFix"
-# - 409 "hasFix"
+# - 341 "needsFix"
+# - 410 "hasFix"
 # - 516 "noFix"
 
 AnalysisOptionsErrorCode.INCLUDED_FILE_PARSE_ERROR:
@@ -2781,9 +2781,7 @@ ParserErrorCode.EXTERNAL_CONSTRUCTOR_WITH_INITIALIZER:
   notes: |-
     Remove the `external` keyword or remove the initializers.
 ParserErrorCode.EXTERNAL_ENUM:
-  status: needsFix
-  notes: |-
-    Remove the `external` keyword.
+  status: hasFix
 ParserErrorCode.EXTERNAL_FACTORY_REDIRECTION:
   status: needsFix
   notes: |-

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -1385,6 +1385,9 @@ final _builtInNonLintProducers = <ErrorCode, List<ProducerGenerator>>{
   ParserErrorCode.EXTERNAL_CLASS: [
     RemoveExtraModifier.new,
   ],
+  ParserErrorCode.EXTERNAL_ENUM: [
+    RemoveExtraModifier.new,
+  ],
   ParserErrorCode.EXTRANEOUS_MODIFIER: [
     RemoveExtraModifier.new,
   ],

pkg/analysis_server/test/src/services/correction/fix/remove_extra_modifier_test.dart

@@ -204,6 +204,15 @@ class C {}
 ''');
   }
 
+  Future<void> test_externalEnum() async {
+    await resolveTestCode(r'''
+external enum E { o }
+''');
+    await assertHasFix('''
+enum E { o }
+''');
+  }
+
   Future<void> test_final_constructor() async {
     await resolveTestCode('''
 class C {