Introduce 'trivial' expressions, use them for this property assignments.

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 397 matching lines @@
     ASSERT(result->is_valid());
     if (result->is_register()) {
       Push(result->reg(), result->number_info());
     } else {
       ASSERT(result->is_constant());
       Push(result->handle());
     }
     result->Unuse();
   }
 
+  // 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).
   void Nip(int num_dropped);
 
  private:
   static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset;
   static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset;
   static const int kContextOffset = StandardFrameConstants::kContextOffset;
 
@@ skipping 152 matching lines @@
   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_