Push version 2.5.7 to trunk....

test/cctest/test-dtoa.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 311 matching lines @@
     int number_digits = current_test.number_digits;
     DoubleToAscii(v, DTOA_PRECISION, number_digits,
                   buffer, &sign, &length, &point);
     CHECK_EQ(0, sign);  // All precomputed numbers are positive.
     CHECK_EQ(current_test.decimal_point, point);
     CHECK_GE(number_digits, length);
     TrimRepresentation(buffer);
     CHECK_EQ(current_test.representation, buffer.start());
   }
 }