flatten Keyword into TokenType

pkg/compiler/lib/src/parser/element_listener.dart

Index: pkg/compiler/lib/src/parser/element_listener.dart
diff --git a/pkg/compiler/lib/src/parser/element_listener.dart b/pkg/compiler/lib/src/parser/element_listener.dart
index 619dbf265adfe0ad33ee5f1375488f72aee9078b..3145497e7b7f1153a8579f574d8f00502e7d503f 100644
--- a/pkg/compiler/lib/src/parser/element_listener.dart
+++ b/pkg/compiler/lib/src/parser/element_listener.dart
@@ -301,7 +301,7 @@ class ElementListener extends Listener {
     if (name.token is KeywordToken) {
       Keyword keyword = (name.token as KeywordToken).keyword;
       if (!keyword.isPseudo) {
-        recoverableError(name, "Illegal name '${keyword.syntax}'.");
+        recoverableError(name, "Illegal name '${keyword.lexeme}'.");
       }
     }
   }