Merge a number of assertion failure fixes to the 3.0 branch.

test/mjsunit/compiler/regress-arguments.js

 // Copyright 2010 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 28 matching lines @@
 for (var i=0; i<1000000; i++) assertEquals(42, h());
 
 var G1 = 21;
 var G2 = 22;
 
 function u() {
  var v = G1 + G2;
  return f.apply(v, arguments);
 }
 
-for (var i=0; i<1000000; i++) assertEquals(void 0, u());
+Number.prototype.foo = 42;
+delete Number.prototype.foo;
+
+for (var i=0; i<100000; i++) assertEquals(void 0, u());