Revert "Merge arguments branch to bleeding merge."

test/mjsunit/regress/regress-70066.js

 // 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 39 matching lines @@
   }
   var value = 2;
   var status = f();
   return value + ":" + status;
 }
 
 assertEquals("2:false", test2(), "test2");
 assertEquals(0, x, "test2");  // Global x is undisturbed.
 
 
-// Delete on a parameter.
+// Delete on an argument.  This hits the same code paths as test5 because
+// 'with' forces all parameters to be indirected through the arguments
+// object.
 function test3(value) {
   var status;
   with ({}) { status = delete value; }
   return value + ":" + status;
 }
 
-assertEquals("3:false", test3(3), "test3");
+assertEquals("undefined:true", test3(3), "test3");
 assertEquals(0, x, "test3");  // Global x is undisturbed.
 
 
-// Delete on a parameter found in an outer context.
+// Delete on an argument from an outer context.  This hits the same code
+// path as test2.
 function test4(value) {
   function f() {
     with ({}) { return delete value; }
   }
   var status = f();
   return value + ":" + status;
 }
 
 assertEquals("4:false", test4(4), "test4");
 assertEquals(0, x, "test4");  // Global x is undisturbed.
 
 
-// Delete on a parameter, arguments object should be unaffected.
+// Delete on an argument found in the arguments object.  Such properties are
+// normally DONT_DELETE in JavaScript but deletion is allowed by V8.
 function test5(value) {
   var status;
   with ({}) { status = delete value; }
   return arguments[0] + ":" + status;
 }
 
-assertEquals("5:false", test5(5), "test5");
+assertEquals("undefined:true", test5(5), "test5");
 assertEquals(0, x, "test5");  // Global x is undisturbed.
 
 function test6(value) {
   function f() {
     with ({}) { return delete value; }
   }
   var status = f();
   return arguments[0] + ":" + status;
 }
 
-assertEquals("6:false", test6(6), "test6");
+assertEquals("undefined:true", test6(6), "test6");
 assertEquals(0, x, "test6");  // Global x is undisturbed.
 
 
 // Delete on a property found on 'with' object.
 function test7(object) {
   with (object) { return delete value; }
 }
 
 var o = {value: 7};
 assertEquals(true, test7(o), "test7");
@@ skipping 20 matching lines @@
 
 
 // Delete on a DONT_DELETE property of the global object.
 var y = 10;
 function test10() {
   with ({}) { return delete y; }
 }
 
 assertEquals(false, test10(), "test10");
 assertEquals(10, y, "test10");