Token of an empty comment reference should end with EOF.

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

Index: pkg/analyzer/lib/src/generated/parser.dart
diff --git a/pkg/analyzer/lib/src/generated/parser.dart b/pkg/analyzer/lib/src/generated/parser.dart
index c90928f8fc26bd1fafc715eb46010b02bfd9d3c7..748fbba36af05e1edab0d3f958fad8723dab227a 100644
--- a/pkg/analyzer/lib/src/generated/parser.dart
+++ b/pkg/analyzer/lib/src/generated/parser.dart
@@ -5033,11 +5033,6 @@ class Parser {
       String referenceSource, int sourceOffset) {
     // TODO(brianwilkerson) The errors are not getting the right offset/length
     // and are being duplicated.
-    if (referenceSource.length == 0) {
-      Token syntheticToken =
-          new SyntheticStringToken(TokenType.IDENTIFIER, "", sourceOffset);
-      return new CommentReference(null, new SimpleIdentifier(syntheticToken));
-    }
     try {
       BooleanErrorListener listener = new BooleanErrorListener();
       Scanner scanner = new Scanner(
@@ -5047,6 +5042,12 @@ class Parser {
       if (listener.errorReported) {
         return null;
       }
+      if (firstToken.type == TokenType.EOF) {
+        Token syntheticToken =
+            new SyntheticStringToken(TokenType.IDENTIFIER, "", sourceOffset);
+        syntheticToken.setNext(firstToken);
+        return new CommentReference(null, new SimpleIdentifier(syntheticToken));
+      }
       Token newKeyword = null;
       if (_tokenMatchesKeyword(firstToken, Keyword.NEW)) {
         newKeyword = firstToken;