Move platform abstraction to base library

src/base/win32-math.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Extra POSIX/ANSI routines for Win32 when using Visual Studio C++. Please
 // refer to The Open Group Base Specification for specification of the correct
 // semantics for these functions.
 // (http://www.opengroup.org/onlinepubs/000095399/)
 #if defined(_MSC_VER) && (_MSC_VER < 1800)
 
 #include "src/base/win32-headers.h"
 #include <float.h>         // Required for DBL_MAX and on Win32 for finite()
 #include <limits.h>        // Required for INT_MAX etc.
 #include <cmath>
-#include "src/win32-math.h"
+#include "src/base/win32-math.h"
 
-#include "src/checks.h"
+#include "src/base/logging.h"
 
 
 namespace std {
 
 // Test for a NaN (not a number) value - usually defined in math.h
 int isnan(double x) {
   return _isnan(x);
 }
 
 
@@ skipping 45 matching lines @@
   // and negative versions of zero.
   if (x == 0)
     return _fpclass(x) & _FPCLASS_NZ;
   else
     return x < 0;
 }
 
 }  // namespace std
 
 #endif  // _MSC_VER