Add a write buffer, aligned so that a single bit tells us whether it has...

src/platform.h

Index: src/platform.h
===================================================================
--- src/platform.h	(revision 6011)
+++ src/platform.h	(working copy)
@@ -44,6 +44,9 @@
 #ifndef V8_PLATFORM_H_
 #define V8_PLATFORM_H_
 
+#include "utils.h"
+#include "v8globals.h"
+
 #define V8_INFINITY INFINITY
 
 // Windows specific stuff.
@@ -123,6 +126,7 @@
 typedef intptr_t AtomicWord;
 
 class Semaphore;
+class Mutex;
 
 double ceiling(double x);
 double modulo(double x, double y);