Some debugging support fixes on ARM simulator port....

src/runtime.cc

 // 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 4779 matching lines @@
   JavaScriptFrameIterator it(id);
   for (; !it.done(); it.Advance()) {
     if (count == index) break;
     count++;
   }
   if (it.done()) return Heap::undefined_value();
 
   // Traverse the saved contexts chain to find the active context for the
   // selected frame.
   SaveContext* save = Top::save_context();
-  while (save != NULL && reinterpret_cast<Address>(save) < it.frame()->sp()) {
+  while (save != NULL && !save->below(it.frame())) {
     save = save->prev();
   }
+  ASSERT(save != NULL);
 
   // Get the frame id.
   Handle<Object> frame_id(WrapFrameId(it.frame()->id()));
 
   // Find source position.
   int position = it.frame()->FindCode()->SourcePosition(it.frame()->pc());
 
   // Check for constructor frame.
   bool constructor = it.frame()->IsConstructor();
 
@@ skipping 479 matching lines @@
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
   JavaScriptFrameIterator it(id);
   JavaScriptFrame* frame = it.frame();
   Handle<JSFunction> function(JSFunction::cast(frame->function()));
   Handle<Code> code(function->code());
   ScopeInfo<> sinfo(*code);
 
   // Traverse the saved contexts chain to find the active context for the
   // selected frame.
   SaveContext* save = Top::save_context();
-  while (save != NULL && reinterpret_cast<Address>(save) < frame->sp()) {
+  while (save != NULL && !save->below(frame)) {
     save = save->prev();
   }
   ASSERT(save != NULL);
   SaveContext savex;
   Top::set_context(*(save->context()));
 
   // Create the (empty) function replacing the function on the stack frame for
   // the purpose of evaluating in the context created below. It is important
   // that this function does not describe any parameters and local variables
   // in the context. If it does then this will cause problems with the lookup
@@ skipping 559 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage();
   }
 }
 
 
 } }  // namespace v8::internal