Implement Math.tan in generated code.

src/math.js

 // Copyright 2006-2008 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 171 matching lines @@
 
 // ECMA 262 - 15.8.2.17
 function MathSqrt(x) {
   if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
   return %_MathSqrt(x);
 }
 
 // ECMA 262 - 15.8.2.18
 function MathTan(x) {
   if (!IS_NUMBER(x)) x = NonNumberToNumber(x);
-  return %Math_tan(x);
+  return %_MathTan(x);
 }
 
 
 // -------------------------------------------------------------------
 
 function SetUpMath() {
   %CheckIsBootstrapping();
   // Set up math constants.
   // ECMA-262, section 15.8.1.1.
   %OptimizeObjectForAddingMultipleProperties($Math, 8);
@@ skipping 52 matching lines @@
     "sqrt", MathSqrt,
     "tan", MathTan,
     "atan2", MathAtan2,
     "pow", MathPow,
     "max", MathMax,
     "min", MathMin
   ));
 }
 
 SetUpMath();