Optimize Math.sin and Math.cos by avoiding runtime calls.

src/x64/codegen-x64.h

Index: src/x64/codegen-x64.h
===================================================================
--- src/x64/codegen-x64.h	(revision 2163)
+++ src/x64/codegen-x64.h	(working copy)
@@ -527,6 +527,12 @@
   // Fast support for Math.random().
   void GenerateRandomPositiveSmi(ZoneList<Expression*>* args);
 
+  // Fast support for Math.sin and Math.cos.
+  enum MathOp { SIN, COS };
+  void GenerateFastMathOp(MathOp op, ZoneList<Expression*>* args);
+  inline void GenerateMathSin(ZoneList<Expression*>* args);
+  inline void GenerateMathCos(ZoneList<Expression*>* args);
+
   // Methods and constants for fast case switch statement support.
   //
   // Only allow fast-case switch if the range of labels is at most