flatten token hierarchy

pkg/analyzer/lib/src/dart/ast/token.dart

Index: pkg/analyzer/lib/src/dart/ast/token.dart
diff --git a/pkg/analyzer/lib/src/dart/ast/token.dart b/pkg/analyzer/lib/src/dart/ast/token.dart
index d0770072a63153e65658acd7a47607f2408c9c25..09da763874e23cec95c69f2f2268c3c64d2e70e8 100644
--- a/pkg/analyzer/lib/src/dart/ast/token.dart
+++ b/pkg/analyzer/lib/src/dart/ast/token.dart
@@ -7,15 +7,11 @@ library analyzer.src.dart.ast.token;
 export 'package:front_end/src/scanner/token.dart'
     show
         BeginToken,
-        BeginTokenWithComment,
         CommentToken,
         DocumentationCommentToken,
         KeywordToken,
-        KeywordTokenWithComment,
         SimpleToken,
         StringToken,
-        StringTokenWithComment,
         SyntheticKeywordToken,
         SyntheticStringToken,
-        TokenClass,
-        TokenWithComment;
+        TokenClass;