Allow the optimizing code generator to call Math.pow with untagged doubles.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
===================================================================
--- src/ia32/lithium-ia32.h	(revision 5948)
+++ src/ia32/lithium-ia32.h	(working copy)
@@ -67,6 +67,7 @@
 //     LLoadKeyedGeneric
 //     LModI
 //     LMulI
+//     LPower
 //     LShiftI
 //     LSubI
 //   LCallConstantFunction
@@ -229,6 +230,7 @@
   V(ObjectLiteral)                              \
   V(OsrEntry)                                   \
   V(Parameter)                                  \
+  V(Power)                                      \
   V(PushArgument)                               \
   V(RegExpLiteral)                              \
   V(Return)                                     \
@@ -1154,6 +1156,16 @@
 };
 
 
+class LPower: public LBinaryOperation {
+ public:
+  LPower(LOperand* left, LOperand* right)
+      : LBinaryOperation(left, right) { }
+
+  DECLARE_CONCRETE_INSTRUCTION(Power, "power")
+  DECLARE_HYDROGEN_ACCESSOR(Power)
+};
+
+
 class LArithmeticD: public LBinaryOperation {
  public:
   LArithmeticD(Token::Value op, LOperand* left, LOperand* right)