[turbofan] Optimize Int32Mod by power-of-two.

test/mjsunit/asm/int32-tmod.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";
+  function f0(i) {
+    i = i|0;
+    return i % 2 | 0;
+  }
   function f1(i) {
     i = i|0;
     return i % 3 | 0;
   }
   function f2(i) {
     i = i|0;
     return i % 9 | 0;
   }
   function f3(i) {
     i = i|0;
     return i % 1024 | 0;
   }
   function f4(i) {
     i = i|0;
     return i % 3333339 | 0;
   }
-  return { f1: f1, f2: f2, f3: f3, f4: f4 };
+  return { f0: f0, f1: f1, f2: f2, f3: f3, f4: f4 };
 }
 
 var m = Module(this, {}, new ArrayBuffer(1024));
 
 for (var i = -2147483648; i < 2147483648; i += 3999773) {
+  assertEquals(i % 2 | 0, m.f0(i));
   assertEquals(i % 3 | 0, m.f1(i));
   assertEquals(i % 9 | 0, m.f2(i));
   assertEquals(i % 1024 | 0, m.f3(i));
   assertEquals(i % 3333339 | 0, m.f4(i));
 }