Allow error-recovery in top-level nodes.

dart/frog/leg/scanner/node_scanner_bench.dart

 // Copyright (c) 2011, 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.
 
 #library('node_scanner_bench');
 #import('../../lib/node/node.dart');
 #import('scannerlib.dart');
 #import('scanner_implementation.dart');
 #import('scanner_bench.dart');
 #source('byte_strings.dart');
 #source('byte_array_scanner.dart');
 
 class NodeScannerBench extends ScannerBench {
   int getBytes(String filename, void callback(bytes)) {
-    List s = fs.readFileSync(filename, null);
+    // This actually returns a buffer, not a String.
+    var s = fs.readFileSync(filename, null);
     callback(s);
     return s.length;
   }
 
   Scanner makeScanner(bytes) => new ByteArrayScanner(bytes);
 
   void checkExistence(String filename) {
     if (!path.existsSync(filename)) {
       throw "no such file: ${filename}";
     }
   }
 }
 
 main() {
   new NodeScannerBench().main(argv);
 }