Added sqrt and pow for arm and x64 - to fix build failures.

src/mips/codegen-mips.h

Index: src/mips/codegen-mips.h
===================================================================
--- src/mips/codegen-mips.h	(revision 4053)
+++ src/mips/codegen-mips.h	(working copy)
@@ -247,8 +247,11 @@
   void GenerateNumberToString(ZoneList<Expression*>* args);
 
   // Fast support for Math.pow().
-  void GeneratePow(ZoneList<Expression*>* args);
+  void GenerateMathPow(ZoneList<Expression*>* args);
+  // Fast support for Math.sqrt().
+  void GenerateMathPow(ZoneList<Expression*>* args);
 
+
   // Fast support for Math.sin and Math.cos.
   inline void GenerateMathSin(ZoneList<Expression*>* args);
   inline void GenerateMathCos(ZoneList<Expression*>* args);