[turbofan] Fix bit representation of NumberConstant.

test/mjsunit/compiler/regress-bit-number-constant.js

+// Copyright 2015 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.
+
+var stdlib = this;
+var buffer = new ArrayBuffer(64 * 1024);
+var foreign = {}
+
+var foo = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  function foo(i) {
+    return !(i ? 1 : false);
+  }
+  return {foo:foo};
+})(stdlib, foreign, buffer).foo;
+
+assertFalse(foo(1));