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

src/platform-win32.cc

Index: src/platform-win32.cc
===================================================================
--- src/platform-win32.cc	(revision 10912)
+++ src/platform-win32.cc	(working copy)
@@ -539,6 +539,10 @@
 
 
 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