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

src/platform-nullos.cc

 // Copyright 2006-2008 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 168 matching lines @@
   UNIMPLEMENTED();
   return 0;
 }
 
 
 bool OS::ArmCpuHasFeature(CpuFeature feature) {
   UNIMPLEMENTED();
 }
 
 
+bool OS::ArmUsingHardFloat() {
+  UNIMPLEMENTED();
+}
+
+
 bool OS::IsOutsideAllocatedSpace(void* address) {
   UNIMPLEMENTED();
   return false;
 }
 
 
 size_t OS::AllocateAlignment() {
   UNIMPLEMENTED();
   return 0;
 }
@@ skipping 266 matching lines @@
 }
 
 
 void ProfileSampler::Stop() {
   UNIMPLEMENTED();
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal