Implement date library functions in C++.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 71fe8838f87b260f69d74db209f9e17b2879ccc1..b6d976a49ac2ab3b057d8da822128aec0444e6ff 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -36,6 +36,7 @@
 #include "contexts.h"
 #include "execution.h"
 #include "frames.h"
+#include "date.h"
 #include "global-handles.h"
 #include "handles.h"
 #include "hashmap.h"
@@ -1017,6 +1018,10 @@ class Isolate {
     return OS::TimeCurrentMillis() - time_millis_at_init_;
   }
 
+  DateCache* date_cache() {
+    return &date_cache_;
+  }
+
  private:
   Isolate();
 
@@ -1194,6 +1199,9 @@ class Isolate {
   // Time stamp at initialization.
   double time_millis_at_init_;
 
+
+  DateCache date_cache_;
+
 #if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   bool simulator_initialized_;
@@ -1389,6 +1397,7 @@ inline void Context::mark_out_of_memory() {
 }
 
 
+
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_