Add an assigned variables analysis....

src/ia32/virtual-frame-ia32.h

 // Copyright 2009 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 404 matching lines @@
 
   // Pushing an expression expects that the expression is trivial (according
   // to Expression::IsTrivial).
   void Push(Expression* expr);
 
   // Nip removes zero or more elements from immediately below the top
   // of the frame, leaving the previous top-of-frame value on top of
   // the frame.  Nip(k) is equivalent to x = Pop(), Drop(k), Push(x).
   inline void Nip(int num_dropped);
 
+  // Update the type information of a local variable frame element directly.
+  inline void SetTypeForLocalAt(int index, NumberInfo info);
+
  private:
   static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset;
   static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset;
   static const int kContextOffset = StandardFrameConstants::kContextOffset;
 
   static const int kHandlerSize = StackHandlerConstants::kSize / kPointerSize;
   static const int kPreallocatedElements = 5 + 8;  // 8 expression stack slots.
 
   ZoneList<FrameElement> elements_;
 
@@ skipping 155 matching lines @@
   inline bool Equals(VirtualFrame* other);
 
   // Classes that need raw access to the elements_ array.
   friend class DeferredCode;
   friend class JumpTarget;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_VIRTUAL_FRAME_IA32_H_