Dead code elimination of inlined arguments objects causes wrong deopt info to...

Dead code elimination of inlined arguments objects causes wrong deopt info to be generated - instead of materializing the arguments, we get 'undefined'.

Golem says the change is perf-neutral.

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/208683006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20529 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.h

@@ -3378,8 +3378,6 @@ class HArgumentsObject V8_FINAL : public HDematerializedObject {
     set_representation(Representation::Tagged());
     SetFlag(kIsArguments);
   }
-
-  virtual bool IsDeletable() const V8_FINAL V8_OVERRIDE { return true; }
 };
 
 

test/mjsunit/regress/regress-355486.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+function f() { var v = arguments[0]; }
+function g() { f(); }
+
+g();
+g();
+%OptimizeFunctionOnNextCall(g);
+g();