Fixes for compilation of Blink on VS2013

Source/wtf/MathExtras.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 95 matching lines @@
     return log(num) / 0.693147180559945309417232121458176568;
 }
 
 inline float log2f(float num)
 {
     // This constant is roughly M_LN2, which is not provided by default on Windows and Android.
     return logf(num) / 0.693147180559945309417232121458176568f;
 }
 #endif
 
-#if COMPILER(MSVC)
+#if COMPILER(MSVC) && (_MSC_VER < 1800)
 
 namespace std {
 
 inline bool isinf(double num) { return !_finite(num) && !_isnan(num); }
 inline bool isnan(double num) { return !!_isnan(num); }
 inline bool isfinite(double x) { return _finite(x); }
 inline bool signbit(double num) { return _copysign(1.0, num) < 0; }
 
 } // namespace std
 
@@ skipping 179 matching lines @@
     if (i >> 2)
         log2 += 2, i >>= 2;
     if (i >> 1)
         log2 += 1;
     return log2;
 }
 
 } // namespace WTF
 
 #endif // #ifndef WTF_MathExtras_h