Move platform abstraction to base library

src/fixed-dtoa.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.
 
 #include <cmath>
 
 #include "include/v8stdint.h"
-#include "src/checks.h"
+#include "src/base/logging.h"
 #include "src/utils.h"
 
 #include "src/double.h"
 #include "src/fixed-dtoa.h"
 
 namespace v8 {
 namespace internal {
 
 // Represents a 128bit type. This class should be replaced by a native type on
 // platforms that support 128bit integers.
@@ skipping 356 matching lines @@
   buffer[*length] = '\0';
   if ((*length) == 0) {
     // The string is empty and the decimal_point thus has no importance. Mimick
     // Gay's dtoa and and set it to -fractional_count.
     *decimal_point = -fractional_count;
   }
   return true;
 }
 
 } }  // namespace v8::internal