[asm] Fix lots of invalid asm.js tests

test/mjsunit/asm/float32array-store-div.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 function Module(stdlib, foreign, heap) {
   "use asm";
   var MEM32 = new stdlib.Float32Array(heap);
   function foo(i) {
-    MEM32[0] = (i >>> 0) / 2;
-    return MEM32[0];
+    i = i | 0;
+    MEM32[0] = +(i >>> 0) / 2.;
+    return +MEM32[0];
   }
   return { foo: foo };
 }
 
 var foo = Module(this, {}, new ArrayBuffer(64 * 1024)).foo;
 assertEquals(0.5, foo(1));