Implement hardfloat calling convention in macro assembler and 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 5250638355d8682559b8558f56517883dee6ba83..fa5466d35238222490eac731e8a790561515af2f 100644
--- a/src/arm/simulator-arm.h
+++ b/src/arm/simulator-arm.h
@@ -310,9 +310,10 @@ class Simulator {
       void* external_function,
       v8::internal::ExternalReference::Type type);
 
-  // For use in calls that take two double values, constructed from r0, r1, r2
-  // and r3.
+  // 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);
   void SetFpResult(const double& result);
   void TrashCallerSaveRegisters();