Fix DeferredTaggedToINoSSE2 to not unconditionally untag undefined to 0.

test/mjsunit/regress/regress-convert-hole.js

 // Copyright 2013 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 77 matching lines @@
   } else {
     d = o[i];
   }
   if (test2) {
     d += 1;
   }
   if (test3) {
     d = d|0;
   }
   a[d] = 1;
+  assertEquals(1, a[d]);
   return d;
 }
 
 var a2 = new Int32Array(10);
 f_external(true, false, true, a2, 0);
 f_external(true, true, true, a2, 0);
 f_external(false, false, true, a2, 1);
 f_external(false, true, true, a2, 1);
 %OptimizeFunctionOnNextCall(f_external);
 f_external(false, false, false, a2, 2);
 assertEquals(1, a2[undefined]);