Add #library tag to please the testing setup we use on the build bots.

tests/corelib/math_parse_double_test.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.
 
 // We temporarily test both the new math library and the old Math
 // class. This can easily be simplified once we get rid of the Math
 // class entirely.
+#library('math_parse_double_test');
 #import('dart:math', prefix: 'math');
 
 double parseDouble(String string) {
   num x = Math.parseDouble(string);
   num y = math.parseDouble(string);
   Expect.equals(x, y);
   return x;
 }
 
 void parseDoubleThrowsFormatException(str) {
@@ skipping 101 matching lines @@
   parseDoubleThrowsFormatException(" -5. ");
   parseDoubleThrowsFormatException("1234567.e2");
   parseDoubleThrowsFormatException(" 1234567.e2 ");
   parseDoubleThrowsFormatException(" +1234567.e2 ");
   parseDoubleThrowsFormatException(" -1234567.e2 ");
   parseDoubleThrowsFormatException("+0x1234567890");
   parseDoubleThrowsFormatException("   +0x1234567890   ");
   parseDoubleThrowsFormatException("   +0x100   ");
   parseDoubleThrowsFormatException("+0x100");
 }