Change handle creation to use Object*, to comply with strict aliasing rules.

src/handles.h

Index: src/handles.h
===================================================================
--- src/handles.h	(revision 2114)
+++ src/handles.h	(working copy)
@@ -119,15 +119,15 @@
   static int NumberOfHandles();
 
   // Creates a new handle with the given value.
-  static inline void** CreateHandle(void* value) {
+  static inline Object** CreateHandle(Object* value) {
     void** result = current_.next;
     if (result == current_.limit) result = Extend();
     // Update the current next field, set the value in the created
     // handle, and return the result.
     ASSERT(result < current_.limit);
     current_.next = result + 1;
-    *result = value;
-    return result;
+    *reinterpret_cast<Object**>(result) = value;
+    return reinterpret_cast<Object**>(result);
   }
 
  private: