Move frog/leg to lib/compiler/implementation.

frog/leg/scanner/d8_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('d8_scanner_bench');
-#import('../../lib/node/node.dart');
-#import('scannerlib.dart');
-#import('scanner_implementation.dart');
-#import('scanner_bench.dart');
-
-d8_read(String filename) native 'return read(filename)';
-
-class D8ScannerBench extends ScannerBench {
-  int getBytes(String filename, void callback(bytes)) {
-    // This actually returns a buffer, not a String.
-    var s = d8_read(filename);
-    callback(s);
-    return s.length;
-  }
-
-  Scanner makeScanner(bytes) => new StringScanner(bytes);
-
-  void checkExistence(String filename) {
-  }
-}
-
-main() {
-  new D8ScannerBench().main(argv);
-}