Break up another large file

pkg/analyzer/test/generated/scanner_test.dart

 // Copyright (c) 2014, 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 analyzer.test.generated.scanner_test;
 
 import 'package:analyzer/dart/ast/token.dart';
+import 'package:analyzer/error/error.dart';
+import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
-import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 import 'package:unittest/unittest.dart';
 
 import '../utils.dart';
 import 'test_support.dart';
 
 main() {
   initializeTestEnvironment();
   defineReflectiveTests(CharSequenceReaderTest);
@@ skipping 1407 matching lines @@
     expect(TokenType.LT_LT.isUserDefinableOperator, isTrue);
     expect(TokenType.MINUS.isUserDefinableOperator, isTrue);
     expect(TokenType.PERCENT.isUserDefinableOperator, isTrue);
     expect(TokenType.PLUS.isUserDefinableOperator, isTrue);
     expect(TokenType.SLASH.isUserDefinableOperator, isTrue);
     expect(TokenType.STAR.isUserDefinableOperator, isTrue);
     expect(TokenType.TILDE.isUserDefinableOperator, isTrue);
     expect(TokenType.TILDE_SLASH.isUserDefinableOperator, isTrue);
   }
 }