Shorten live ranges for arguments to runtime calls.

src/hydrogen-instructions.h

 // Copyright 2011 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 1030 matching lines @@
 class HLeaveInlined: public HInstruction {
  public:
   HLeaveInlined() {}
 
   DECLARE_CONCRETE_INSTRUCTION(LeaveInlined, "leave_inlined")
 };
 
 
 class HPushArgument: public HUnaryOperation {
  public:
-  explicit HPushArgument(HValue* value) : HUnaryOperation(value) { }
+  explicit HPushArgument(HValue* value) : HUnaryOperation(value) {
+    set_representation(Representation::Tagged());
+  }
 
   virtual Representation RequiredInputRepresentation(int index) const {
     return Representation::Tagged();
   }
 
   HValue* argument() const { return OperandAt(0); }
 
   DECLARE_CONCRETE_INSTRUCTION(PushArgument, "push_argument")
 };
 
@@ skipping 2364 matching lines @@
   HValue* object() const { return left(); }
   HValue* key() const { return right(); }
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_