Move platform abstraction to base library

src/base/win32-math.cc

Index: src/base/win32-math.cc
diff --git a/src/win32-math.cc b/src/base/win32-math.cc
similarity index 97%
rename from src/win32-math.cc
rename to src/base/win32-math.cc
index 1e34b8843b9d1f421f9a00f57d55f3b51a4ab3ec..df70cd0b744cdb704d938d154f4d1395fac64337 100644
--- a/src/win32-math.cc
+++ b/src/base/win32-math.cc
@@ -12,9 +12,9 @@
 #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 {