ARM: Support hardfloat in SCons build and make it a build time setting

src/arm/simulator-arm.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 182 matching lines @@
   uintptr_t PopAddress();
 
   // ICache checking.
   static void FlushICache(v8::internal::HashMap* i_cache, void* start,
                           size_t size);
 
   // Returns true if pc register contains one of the 'special_values' defined
   // below (bad_lr, end_sim_pc).
   bool has_bad_pc() const;
 
+  // EABI variant for double arguments in use.
+  bool use_eabi_hardfloat() {
+#if USE_EABI_HARDFLOAT
+    return true;
+#else
+    return false;
+#endif
+  }
+
  private:
   enum special_values {
     // Known bad pc value to ensure that the simulator does not execute
     // without being properly setup.
     bad_lr = -1,
     // A pc value used to signal the simulator to stop execution.  Generally
     // the lr is set to this value on transition from native C code to
     // simulated execution, so that the simulator can "return" to the native
     // C code.
     end_sim_pc = -2
@@ skipping 197 matching lines @@
 
   static inline void UnregisterCTryCatch() {
     Simulator::current(Isolate::Current())->PopAddress();
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // !defined(USE_SIMULATOR)
 #endif  // V8_ARM_SIMULATOR_ARM_H_