Set x87 FPU precision to 64-bit for MinGW on V8 init to fix failing test

src/platform-win32.cc

 // Copyright 2012 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 521 matching lines @@
 // Returns a string identifying the current timezone for the
 // timestamp taking into account daylight saving.
 char* Time::LocalTimezone() {
   // Return the standard or DST time zone name based on whether daylight
   // saving is in effect at the given time.
   return InDST() ? dst_tz_name_ : std_tz_name_;
 }
 
 
 void OS::SetUp() {
+#ifdef __MINGW32__
+  // Set x87 FPU precision to 64-bit to be consistent with MSVC.
+  _controlfp(_PC_53, _MCW_PC);
+#endif
   // Seed the random number generator.
   // Convert the current time to a 64-bit integer first, before converting it
   // to an unsigned. Going directly can cause an overflow and the seed to be
   // set to all ones. The seed will be identical for different instances that
   // call this setup code within the same millisecond.
   uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
   srand(static_cast<unsigned int>(seed));
   limit_mutex = CreateMutex();
 }
 
@@ skipping 1521 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal