MetadataAnnotation should be spannable.

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 part of dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 432 matching lines @@
       node = currentElement;
     }
     if (node is Node) {
       return spanFromNode(node, uri);
     } else if (node is Token) {
       return spanFromTokens(node, node, uri);
     } else if (node is HInstruction) {
       return spanFromHInstruction(node);
     } else if (node is Element) {
       return spanFromElement(node);
+    } else if (node is MetadataAnnotation) {
+      return spanFromTokens(node.beginToken, node.endToken);
     } else {
       throw 'No error location.';
     }
   }
 
   void reportFatalError(String reason, Element element,
                         {Node node, Token token, HInstruction instruction}) {
     withCurrentElement(element, () {
       cancel(reason, node: node, token: token, instruction: instruction,
              element: element);
@@ skipping 653 matching lines @@
 
   void close() {}
 
   toString() => name;
 
   /// Convenience method for getting an [api.CompilerOutputProvider].
   static NullSink outputProvider(String name, String extension) {
     return new NullSink('$name.$extension');
   }
 }