report const class as a more specific error code

pkg/analyzer/lib/src/fasta/ast_builder.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.analyzer.ast_builder;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast_factory.dart' show AstFactory;
 import 'package:analyzer/dart/ast/standard_ast_factory.dart' as standard;
 import 'package:analyzer/dart/ast/token.dart' show Token, TokenType;
@@ skipping 1916 matching lines @@
         }
       }
       return text;
     }
 
     switch (code.analyzerCode) {
       case "EXPECTED_TYPE_NAME":
         errorReporter?.reportErrorForOffset(
             ParserErrorCode.EXPECTED_TYPE_NAME, charOffset, 1);
         return;
-      case "NATIVE_CLAUSE_SHOULD_BE_ANNOTATION":
-        if (!allowNativeClause) {
-          errorReporter?.reportErrorForOffset(
-              ParserErrorCode.NATIVE_CLAUSE_SHOULD_BE_ANNOTATION,
-              charOffset,
-              1);
-        }
+      case "CONST_CLASS":
+        errorReporter?.reportErrorForOffset(
+            ParserErrorCode.CONST_CLASS, charOffset, 1);
         return;
       case "EXPECTED_STRING_LITERAL":
         errorReporter?.reportErrorForOffset(
             ParserErrorCode.EXPECTED_STRING_LITERAL, charOffset, 1);
         return;
       case "EXTRANEOUS_MODIFIER":
         String text = stringOrTokenLexeme();
         errorReporter?.reportErrorForOffset(ParserErrorCode.EXTRANEOUS_MODIFIER,
             charOffset, text.length, [text]);
         return;
+      case "NATIVE_CLAUSE_SHOULD_BE_ANNOTATION":
+        if (!allowNativeClause) {
+          errorReporter?.reportErrorForOffset(
+              ParserErrorCode.NATIVE_CLAUSE_SHOULD_BE_ANNOTATION,
+              charOffset,
+              1);
+        }
+        return;
       case "UNEXPECTED_TOKEN":
         String text = stringOrTokenLexeme();
         if (text == ';') {
           errorReporter?.reportErrorForOffset(
               ParserErrorCode.EXPECTED_TOKEN, charOffset, text.length, [text]);
         } else {
           errorReporter?.reportErrorForOffset(ParserErrorCode.UNEXPECTED_TOKEN,
               charOffset, text.length, [text]);
         }
         return;
@@ skipping 112 matching lines @@
       } else if (identical('var', s)) {
         finalConstOrVarKeyword = token;
       } else if (identical('covariant', s)) {
         covariantKeyword = token;
       } else {
         unhandled("$s", "modifier", token.charOffset, null);
       }
     }
   }
 }