Move more builtin files to strict mode.

src/math.js

 // Copyright 2012 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.
 
+"use strict";
+
 // This file relies on the fact that the following declarations have been made
 // in runtime.js:
 // var $Object = global.Object;
 
 // Keep reference to original values of some global properties.  This
 // has the added benefit that the code in this file is isolated from
 // changes to these properties.
 var $floor = MathFloor;
 var $abs = MathAbs;
 
@@ skipping 288 matching lines @@
 
   %SetInlineBuiltinFlag(MathCeil);
   %SetInlineBuiltinFlag(MathRandom);
   %SetInlineBuiltinFlag(MathSin);
   %SetInlineBuiltinFlag(MathCos);
   %SetInlineBuiltinFlag(MathTan);
   %SetInlineBuiltinFlag(TrigonometricInterpolation);
 }
 
 SetUpMath();