Fix build with MinGW-w64

googletest/include/gtest/internal/gtest-port.h

@@ -396,7 +396,7 @@
 #  include <io.h>
 # endif
 // In order to avoid having to include <windows.h>, use forward declaration
-#if GTEST_OS_WINDOWS_MINGW
+#if GTEST_OS_WINDOWS_MINGW && !defined(__MINGW64_VERSION_MAJOR)
 // MinGW defined _CRITICAL_SECTION and _RTL_CRITICAL_SECTION as two
 // separate (equivalent) structs, instead of using typedef
 typedef struct _CRITICAL_SECTION GTEST_CRITICAL_SECTION;