Fix code generation for fast smi loops to support parameters as well....

test/mjsunit/compiler/loopcount.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 66 matching lines @@
 assertEquals(0x40000002, f8());
 
 
 function f9() {
   var i;
   for (i = 0; i < 42; i++) {
     return 42;
   }
 }
 assertEquals(42, f9());
+
+
+function f10(x) {
+  for (x = 0; x < 4; x++) {}
+}
+f10(42);