Change NaN-test to only check for QNaNs, and API to only introduce QNaNs.

src/platform-win32.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 1315 matching lines @@
 #pragma warning(pop)
 
 #else  // __MINGW32__
 void OS::LogSharedLibraryAddresses() { }
 int OS::StackWalk(Vector<OS::StackFrame> frames) { return 0; }
 #endif  // __MINGW32__
 
 
 double OS::nan_value() {
 #ifdef _MSC_VER
-  static const __int64 nanval = 0xfff8000000000000;
+  // Positive Quiet NaN with no payload (aka. Indeterminate) has all bits
+  // in mask set, so value equals mask.
+  static const __int64 nanval = kQuietNaNMask;
   return *reinterpret_cast<const double*>(&nanval);
 #else  // _MSC_VER
   return NAN;
 #endif  // _MSC_VER
 }
 
 
 int OS::ActivationFrameAlignment() {
 #ifdef _WIN64
   return 16;  // Windows 64-bit ABI requires the stack to be 16-byte aligned.
@@ skipping 558 matching lines @@
 
   // Release the thread handles
   CloseHandle(data_->sampler_thread_);
   CloseHandle(data_->profiled_thread_);
 }
 
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal