Prevent double reporting on hex, strings, and multiline comments.

sdk/lib/_internal/compiler/implementation/scanner/listener.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/listener.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
index 22596d4ea39f08876fb9f940fd2bad4aa477a743..b90d9fd6bee1a112abf3f28c6dd910d3f3432bf2 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
@@ -634,13 +634,13 @@ class Listener {
     return skipToEof(token);
   }
 
-  Link<Token> expectedDeclaration(Token token) {
+  Token expectedDeclaration(Token token) {
     if (token is ErrorToken) {
       reportErrorToken(token);
     } else {
       error("expected a declaration, but got '${token.value}'", token);
     }
-    return const Link<Token>();
+    return skipToEof(token);
   }
 
   Token unmatched(Token token) {
@@ -1213,14 +1213,14 @@ class ElementListener extends Listener {
     return unexpected(token);
   }
 
-  Link<Token> expectedDeclaration(Token token) {
+  Token expectedDeclaration(Token token) {
     if (token is ErrorToken) {
       reportErrorToken(token);
     } else {
       reportFatalError(token,
                        "Expected a declaration, but got '${token.value}'.");
     }
-    return const Link<Token>();
+    return skipToEof(token);
   }
 
   Token unmatched(Token token) {