Experimental: this is a substantial change to allow the virtual frame...

src/codegen-ia32.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 430 matching lines @@
   // positions are collected by the assembler and emitted with the relocation
   // information.
   void CodeForStatement(Node* node);
   void CodeForSourcePosition(int pos);
 
   // Is the given jump target the actual (ie, non-shadowed) function return
   // target?
   bool IsActualFunctionReturn(JumpTarget* target);
 
   bool is_eval_;  // Tells whether code is generated for eval.
+
+#ifdef DEBUG
+  // True if the registers are valid for entry to a block.  There should be
+  // no frame-external references to eax, ebx, ecx, edx, or edi.
+  bool HasValidEntryRegisters();
+#endif
+
   Handle<Script> script_;
   List<DeferredCode*> deferred_;
 
   // Assembler
   MacroAssembler* masm_;  // to generate code
 
   // Code generation state
   Scope* scope_;
   VirtualFrame* frame_;
   RegisterAllocator* allocator_;
@@ skipping 31 matching lines @@
   cgen_->set_in_spilled_code(false);
   GetValue(typeof_state);
   cgen_->frame()->SpillAll();
   cgen_->set_in_spilled_code(true);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODEGEN_IA32_H_