Fix some bugs related to the covariant keyword

pkg/analyzer/test/generated/parser_test.dart

Index: pkg/analyzer/test/generated/parser_test.dart
diff --git a/pkg/analyzer/test/generated/parser_test.dart b/pkg/analyzer/test/generated/parser_test.dart
index 221755ab831d083c9e64d22756696652865137a3..2701839bca376b56de0f8371a6e51631bf7dc8c3 100644
--- a/pkg/analyzer/test/generated/parser_test.dart
+++ b/pkg/analyzer/test/generated/parser_test.dart
@@ -987,6 +987,14 @@ class ErrorParserTest extends ParserTestCase {
     listener.assertErrorsWithCodes([ParserErrorCode.DUPLICATED_MODIFIER]);
   }
 
+  void test_duplicatedModifier_covariant() {
+    createParser('covariant covariant m;');
+    FormalParameter parameter =
+        parser.parseFormalParameter(ParameterKind.REQUIRED);
+    expectNotNullIfNoErrors(parameter);
+    listener.assertErrorsWithCodes([ParserErrorCode.DUPLICATED_MODIFIER]);
+  }
+
   void test_duplicatedModifier_external() {
     createParser('external external f();');
     ClassMember member = parser.parseClassMember('C');
@@ -8991,7 +8999,7 @@ void''');
 
   void test_parseFormalParameter_covariant_type_normal() {
     ParameterKind kind = ParameterKind.REQUIRED;
-    createParser('covariant A a');
+    createParser('covariant A<B<C>> a');
     FormalParameter parameter = parser.parseFormalParameter(kind);
     expectNotNullIfNoErrors(parameter);
     listener.assertNoErrors();