Make it possible to add a user data object to each script compiled

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 1746)
+++ src/objects.h	(working copy)
@@ -2603,6 +2603,9 @@
   // extracted.
   DECL_ACCESSORS(column_offset, Smi)
 
+  // [data]: additional data associated with this script.
+  DECL_ACCESSORS(data, Object)
+
   // [wrapper]: the wrapper cache.
   DECL_ACCESSORS(wrapper, Proxy)
 
@@ -2623,7 +2626,8 @@
   static const int kNameOffset = kSourceOffset + kPointerSize;
   static const int kLineOffsetOffset = kNameOffset + kPointerSize;
   static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize;
-  static const int kWrapperOffset = kColumnOffsetOffset + kPointerSize;
+  static const int kDataOffset = kColumnOffsetOffset + kPointerSize;
+  static const int kWrapperOffset = kDataOffset + kPointerSize;
   static const int kTypeOffset = kWrapperOffset + kPointerSize;
   static const int kLineEndsOffset = kTypeOffset + kPointerSize;
   static const int kIdOffset = kLineEndsOffset + kPointerSize;