quick fix for INTERFACE_MIXIN

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

Change-Id: I536eb9bf75ad1c7df3e697c75874954f4a882905
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/369503
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Auto-Submit: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

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

@@ -45,8 +45,8 @@
 #
 # Stats:
 # -  42 "needsEvaluation"
-# - 349 "needsFix"
-# - 402  "hasFix"
+# - 348 "needsFix"
+# - 403  "hasFix"
 # - 516 "noFix"
 
 AnalysisOptionsErrorCode.INCLUDED_FILE_PARSE_ERROR:
@@ -2915,9 +2915,7 @@ ParserErrorCode.INITIALIZED_VARIABLE_IN_FOR_EACH:
 ParserErrorCode.INTERFACE_ENUM:
   status: needsEvaluation
 ParserErrorCode.INTERFACE_MIXIN:
-  status: needsFix
-  notes: |-
-    Remove the `interface` keyword.
+  status: hasFix
 ParserErrorCode.INTERFACE_MIXIN_CLASS:
   status: needsFix
   notes: |-

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

@@ -1394,6 +1394,9 @@ final _builtInNonLintProducers = {
   ParserErrorCode.GETTER_WITH_PARAMETERS: [
     RemoveParametersInGetterDeclaration.new,
   ],
+  ParserErrorCode.INTERFACE_MIXIN: [
+    RemoveExtraModifier.new,
+  ],
   ParserErrorCode.INVALID_CONSTANT_PATTERN_BINARY: [
     AddConst.new,
   ],

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

@@ -217,6 +217,15 @@ mixin M {}
 ''');
   }
 
+  Future<void> test_interfaceMixin() async {
+    await resolveTestCode('''
+interface mixin M {}
+''');
+    await assertHasFix('''
+mixin M {}
+''');
+  }
+
   Future<void> test_invalidAsyncConstructorModifier() async {
     await resolveTestCode(r'''
 class A {