Allow moc to handle Unicode output filenames on Windows with MSVC

The C standard library functions cannot handle UTF-8 filenames. Instead,
we need to use the wide-character versions which accept UTF-16 input.

Task-number: QTBUG-65492
Change-Id: If4b3b4eeeec4f3bbb428b8f6b0311a65d01463b0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/tools/moc/main.cpp

@@ -486,8 +486,8 @@ int runMoc(int argc, char **argv)
     // 3. and output meta object code
 
     if (output.size()) { // output file specified
-#if defined(_MSC_VER) && _MSC_VER >= 1400
-        if (fopen_s(&out, QFile::encodeName(output).constData(), "w"))
+#if defined(_MSC_VER)
+        if (_wfopen_s(&out, reinterpret_cast<const wchar_t *>(output.utf16()), L"w") != 0)
 #else
         out = fopen(QFile::encodeName(output).constData(), "w"); // create output file
         if (!out)