Accurate function prototypes for native calls from ARM simulator.

src/arm/simulator-arm.h

Index: src/arm/simulator-arm.h
diff --git a/src/arm/simulator-arm.h b/src/arm/simulator-arm.h
index b918ecf9638a4825163f0f1874f54877a5371bd0..1776887b66774252f39856e7c10c3e1e5b44d1a6 100644
--- a/src/arm/simulator-arm.h
+++ b/src/arm/simulator-arm.h
@@ -347,10 +347,8 @@ class Simulator {
       void* external_function,
       v8::internal::ExternalReference::Type type);
 
-  // For use in calls that take double value arguments.
-  void GetFpArgs(double* x, double* y);
-  void GetFpArgs(double* x);
-  void GetFpArgs(double* x, int32_t* y);
+  // Handle arguments and return value for runtime FP functions.
+  void GetFpArgs(double* x, double* y, int32_t* z);
   void SetFpResult(const double& result);
   void TrashCallerSaveRegisters();