Mark some unused code as being deprecated

pkg/analyzer/lib/src/generated/incremental_scanner.dart

Index: pkg/analyzer/lib/src/generated/incremental_scanner.dart
diff --git a/pkg/analyzer/lib/src/generated/incremental_scanner.dart b/pkg/analyzer/lib/src/generated/incremental_scanner.dart
index ae34471b55058d10286efb582b9673b5def6f6b3..a0bd23863d99d0a317bd78d8b9965b0af6856b67 100644
--- a/pkg/analyzer/lib/src/generated/incremental_scanner.dart
+++ b/pkg/analyzer/lib/src/generated/incremental_scanner.dart
@@ -2,6 +2,7 @@
 // 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.
 
+@deprecated
 library analyzer.src.generated.incremental_scanner;
 
 import "dart:math" as math;
@@ -18,6 +19,7 @@ import 'package:analyzer/src/generated/utilities_collection.dart' show TokenMap;
  * An `IncrementalScanner` is a scanner that scans a subset of a string and
  * inserts the resulting tokens into the middle of an existing token stream.
  */
+@deprecated
 class IncrementalScanner {
   /**
    * The source being scanned.