Add a workaround for a compiler gug in GCC 4.2.3. See issue 122 for details....

src/top.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 276 matching lines @@
   static int break_id_;
 
   friend class SaveContext;
   friend class AssertNoContextChange;
   friend class ExecutionAccess;
 
   static void FillCache();
 };
 
 
+// TODO(122): If the GCC version is 4.2.0 or higher an additional field is added
+// to this class as a workarround for a bug in the generated code found with
+// GCC 4.2.3.
 class SaveContext BASE_EMBEDDED {
  public:
   SaveContext() :
       context_(Top::context()),
+#if __GNUC_VERSION__ >= 40200
+      dummy_(Top::context()),
+#endif
       prev_(Top::save_context()) {
     Top::set_save_context(this);
   }
 
   ~SaveContext() {
     Top::set_context(*context_);
     Top::set_save_context(prev_);
   }
 
   Handle<Context> context() { return context_; }
   SaveContext* prev() { return prev_; }
 
  private:
   Handle<Context> context_;
+#if __GNUC_VERSION__ >= 40200
+  Handle<Context> dummy_;
+#endif
   SaveContext* prev_;
 };
 
 
 class AssertNoContextChange BASE_EMBEDDED {
 #ifdef DEBUG
  public:
   AssertNoContextChange() :
       context_(Top::context()) {
   }
@@ skipping 14 matching lines @@
 
 class ExecutionAccess BASE_EMBEDDED {
  public:
   ExecutionAccess();
   ~ExecutionAccess();
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_TOP_H_